fix checks for drive mirror with bitmap

The QAPI change for QEMU 8.0 dropped redundant has_foo parameters, but
in the blockdev_mirror_common() function (which is not part of the
QAPI itself but called from there) the argument pair was has_bitmap
and bitmap_name rather than has_bitmap and bitmap.

Reported-by: Aaron Lauterer <a.lauterer@proxmox.com>
Signed-off-by: Fiona Ebner <f.ebner@proxmox.com>

debian/patches/bitmap-mirror/0006-mirror-move-some-checks-to-qmp.patch

@@ -62,7 +62,7 @@ index f42953837b..8f79efaa87 100644
  
          if (bitmap_mode != BITMAP_SYNC_MODE_NEVER) {
 diff --git a/blockdev.c b/blockdev.c
-index 19f490fce7..9a010f3a86 100644
+index e6b2b1e338..bdae211a54 100644
 --- a/blockdev.c
 +++ b/blockdev.c
 @@ -3015,7 +3015,36 @@ static void blockdev_mirror_common(const char *job_id, BlockDriverState *bs,
@@ -72,7 +72,7 @@ index 19f490fce7..9a010f3a86 100644
 +    if ((sync == MIRROR_SYNC_MODE_BITMAP) ||
 +        (sync == MIRROR_SYNC_MODE_INCREMENTAL)) {
 +        /* done before desugaring 'incremental' to print the right message */
-+        if (!bitmap) {
++        if (!bitmap_name) {
 +            error_setg(errp, "Must provide a valid bitmap name for "
 +                       "'%s' sync mode", MirrorSyncMode_str(sync));
 +            return;
@@ -93,7 +93,7 @@ index 19f490fce7..9a010f3a86 100644
 +        bitmap_mode = BITMAP_SYNC_MODE_ON_SUCCESS;
 +    }
 +
-     if (bitmap) {
+     if (bitmap_name) {
 +        if (sync != MIRROR_SYNC_MODE_BITMAP) {
 +            error_setg(errp, "Sync mode '%s' not supported with bitmap.",
 +                       MirrorSyncMode_str(sync));