vl: Reduce scope of variables in configure_accelerators

The accel_list and tmp variables are only used when manufacturing
-machine accel, options based on -accel.

Acked-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed by: Aleksandar Markovic <amarkovic@wavecomp.com>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>

vl.c

@@ -2755,7 +2755,6 @@ static int do_configure_accelerator(void *opaque, QemuOpts *opts, Error **errp)
 static void configure_accelerators(const char *progname)
 {
     const char *accel;
-    char **accel_list, **tmp;
     bool init_failed = false;
 
     qemu_opts_foreach(qemu_find_opts("icount"),
@@ -2763,6 +2762,8 @@ static void configure_accelerators(const char *progname)
 
     accel = qemu_opt_get(qemu_get_machine_opts(), "accel");
     if (QTAILQ_EMPTY(&qemu_accel_opts.head)) {
+        char **accel_list, **tmp;
+
         if (accel == NULL) {
             /* Select the default accelerator */
             if (!accel_find("tcg") && !accel_find("kvm")) {