cocci: Do not initialize variable used by QSIMPLEQ_FOREACH macro

The QSIMPLEQ_FOREACH() macro, defined in "qemu/queue.h",
always assigns its iterator variable when entering the
loop. Remove the pointless and possibly misleading
assignment.

Mechanical patch using the following coccinelle spatch:

  @@
  type T;
  identifier e;
  iterator FOREACH_MACRO =~ ".*_FOREACH.*";
  statement S;
  @@
  -    T *e = ...;
  +    T *e;
       ... when != e
       FOREACH_MACRO(e, ...) S

Signed-off-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Reviewed-by: Pierrick Bouvier <pierrick.bouvier@oss.qualcomm.com>
Message-Id: <20260415215539.92629-4-philmd@linaro.org>

block/blkdebug.c

@@ -591,7 +591,7 @@ static int coroutine_fn rule_check(BlockDriverState *bs, uint64_t offset,
                                    uint64_t bytes, BlkdebugIOType iotype)
 {
     BDRVBlkdebugState *s = bs->opaque;
-    BlkdebugRule *rule = NULL;
+    BlkdebugRule *rule;
     int error;
     bool immediately;
 

migration/block-dirty-bitmap.c

@@ -1216,7 +1216,7 @@ fail:
 static int dirty_bitmap_save_setup(QEMUFile *f, void *opaque, Error **errp)
 {
     DBMSaveState *s = &((DBMState *)opaque)->save;
-    SaveBitmapState *dbms = NULL;
+    SaveBitmapState *dbms;
 
     if (init_dirty_bitmap_migration(s, errp) < 0) {
         return -1;