Use error_fatal to simplify obvious fatal errors (again)

Add a slight improvement of the Coccinelle semantic patch from commit
007b06578a, and use it to clean up.  It leaves dead Error * variables
behind, cleaned up manually.

Cc: David Gibson <david@gibson.dropbear.id.au>
Cc: Alexander Graf <agraf@suse.de>
Cc: Eric Blake <eblake@redhat.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Acked-by: David Gibson <david@gibson.dropbear.id.au>
Message-Id: <20181017082702.5581-3-armbru@redhat.com>

hw/intc/xics_kvm.c

@@ -198,17 +198,12 @@ static void ics_get_kvm_state(ICSState *ics)
 {
     uint64_t state;
     int i;
-    Error *local_err = NULL;
 
     for (i = 0; i < ics->nr_irqs; i++) {
         ICSIRQState *irq = &ics->irqs[i];
 
         kvm_device_access(kernel_xics_fd, KVM_DEV_XICS_GRP_SOURCES,
-                          i + ics->offset, &state, false, &local_err);
+                          i + ics->offset, &state, false, &error_fatal);
-        if (local_err) {
-            error_report_err(local_err);
-            exit(1);
-        }
 
         irq->server = state & KVM_XICS_DESTINATION_MASK;
         irq->saved_priority = (state >> KVM_XICS_PRIORITY_SHIFT)

qemu-nbd.c

@@ -1002,11 +1002,7 @@ int main(int argc, char **argv)
     }
 
     exp = nbd_export_new(bs, dev_offset, fd_size, nbdflags, nbd_export_closed,
-                         writethrough, NULL, &local_err);
+                         writethrough, NULL, &error_fatal);
-    if (!exp) {
-        error_report_err(local_err);
-        exit(EXIT_FAILURE);
-    }
     nbd_export_set_name(exp, export_name);
     nbd_export_set_description(exp, export_description);
 

scripts/coccinelle/use-error_fatal.cocci

@@ -0,0 +1,20 @@
+@@
+type T;
+identifier FUN, RET;
+expression list ARGS;
+expression ERR, EC, FAIL;
+@@
+(
+-    T RET = FUN(ARGS, &ERR);
++    T RET = FUN(ARGS, &error_fatal);
+|
+-    RET = FUN(ARGS, &ERR);
++    RET = FUN(ARGS, &error_fatal);
+|
+-    FUN(ARGS, &ERR);
++    FUN(ARGS, &error_fatal);
+)
+-    if (FAIL) {
+-        error_report_err(ERR);
+-        exit(EC);
+-    }

vl.c

@@ -2002,15 +2002,10 @@ static void select_vgahw(const char *p)
 
 static void parse_display_qapi(const char *optarg)
 {
-    Error *err = NULL;
     DisplayOptions *opts;
     Visitor *v;
 
-    v = qobject_input_visitor_new_str(optarg, "type", &err);
+    v = qobject_input_visitor_new_str(optarg, "type", &error_fatal);
-    if (!v) {
-        error_report_err(err);
-        exit(1);
-    }
 
     visit_type_DisplayOptions(v, NULL, &opts, &error_fatal);
     QAPI_CLONE_MEMBERS(DisplayOptions, &dpy, opts);