qemu-option: Check return value instead of @err where convenient

Convert uses like

    opts = qemu_opts_create(..., &err);
    if (err) {
        ...
    }

to

    opts = qemu_opts_create(..., errp);
    if (!opts) {
        ...
    }

Eliminate error_propagate() that are now unnecessary.  Delete @err
that are now unused.

Note that we can't drop parallels_open()'s error_propagate() here.  We
continue to execute it even in the converted case.  It's a no-op then:
local_err is null.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: Greg Kurz <groug@kaod.org>
Message-Id: <20200707160613.848843-8-armbru@redhat.com>

block/parallels.c

@@ -824,8 +824,8 @@ static int parallels_open(BlockDriverState *bs, QDict *options, int flags,
         }
     }
 
-    opts = qemu_opts_create(&parallels_runtime_opts, NULL, 0, &local_err);
+    opts = qemu_opts_create(&parallels_runtime_opts, NULL, 0, errp);
-    if (local_err != NULL) {
+    if (!opts) {
         goto fail_options;
     }
 

blockdev.c

@@ -504,9 +504,8 @@ static BlockBackend *blockdev_init(const char *file, QDict *bs_opts,
     /* Check common options by copying from bs_opts to opts, all other options
      * stay in bs_opts for processing by bdrv_open(). */
     id = qdict_get_try_str(bs_opts, "id");
-    opts = qemu_opts_create(&qemu_common_drive_opts, id, 1, &error);
+    opts = qemu_opts_create(&qemu_common_drive_opts, id, 1, errp);
-    if (error) {
+    if (!opts) {
-        error_propagate(errp, error);
         goto err_no_opts;
     }
 

qdev-monitor.c

@@ -802,9 +802,8 @@ void qmp_device_add(QDict *qdict, QObject **ret_data, Error **errp)
     QemuOpts *opts;
     DeviceState *dev;
 
-    opts = qemu_opts_from_qdict(qemu_find_opts("device"), qdict, &local_err);
+    opts = qemu_opts_from_qdict(qemu_find_opts("device"), qdict, errp);
-    if (local_err) {
+    if (!opts) {
-        error_propagate(errp, local_err);
         return;
     }
     if (!monitor_cur_is_qmp() && qdev_device_help(opts)) {

util/qemu-config.c

@@ -493,9 +493,8 @@ static void config_parse_qdict_section(QDict *options, QemuOptsList *opts,
         goto out;
     }
 
-    subopts = qemu_opts_create(opts, NULL, 0, &local_err);
+    subopts = qemu_opts_create(opts, NULL, 0, errp);
-    if (local_err) {
+    if (!subopts) {
-        error_propagate(errp, local_err);
         goto out;
     }
 
@@ -538,10 +537,9 @@ static void config_parse_qdict_section(QDict *options, QemuOptsList *opts,
             }
 
             opt_name = g_strdup_printf("%s.%u", opts->name, i++);
-            subopts = qemu_opts_create(opts, opt_name, 1, &local_err);
+            subopts = qemu_opts_create(opts, opt_name, 1, errp);
             g_free(opt_name);
-            if (local_err) {
+            if (!subopts) {
-                error_propagate(errp, local_err);
                 goto out;
             }
 

util/qemu-option.c

@@ -670,11 +670,9 @@ void qemu_opts_set(QemuOptsList *list, const char *id,
                    const char *name, const char *value, Error **errp)
 {
     QemuOpts *opts;
-    Error *local_err = NULL;
 
-    opts = qemu_opts_create(list, id, 1, &local_err);
+    opts = qemu_opts_create(list, id, 1, errp);
-    if (local_err) {
+    if (!opts) {
-        error_propagate(errp, local_err);
         return;
     }
     qemu_opt_set(opts, name, value, errp);
@@ -1012,10 +1010,8 @@ QemuOpts *qemu_opts_from_qdict(QemuOptsList *list, const QDict *qdict,
     QemuOpts *opts;
     const QDictEntry *entry;
 
-    opts = qemu_opts_create(list, qdict_get_try_str(qdict, "id"), 1,
+    opts = qemu_opts_create(list, qdict_get_try_str(qdict, "id"), 1, errp);
-                            &local_err);
+    if (!opts) {
-    if (local_err) {
-        error_propagate(errp, local_err);
         return NULL;
     }