qemu-img: Set the ID of the block job in img_commit()

img_commit() creates a block job without an ID. This is no longer
allowed now that we require it to be unique and well-formed. We were
solving this by having a fallback in block_job_create(), but now that
we extended the API of commit_active_start() we can finally set an
explicit ID and revert that change.
Signed-off-by: NAlberto Garcia <berto@igalia.com>
Reviewed-by: NMax Reitz <mreitz@redhat.com>
Reviewed-by: NKevin Wolf <kwolf@redhat.com>
Signed-off-by: NKevin Wolf <kwolf@redhat.com>

blockjob.c

@@ -132,12 +132,6 @@ void *block_job_create(const char *job_id, const BlockJobDriver *driver,
 
     if (job_id == NULL) {
         job_id = bdrv_get_device_name(bs);
-        /* Assign a default ID if the BDS does not have a device
-         * name. We'll get rid of this soon when we finish extending
-         * the API of all commands that create block jobs. */
-        if (job_id[0] == '\0') {
-            job_id = "default_job";
-        }
     }
 
     if (!id_wellformed(job_id)) {

qemu-img.c

@@ -920,7 +920,7 @@ static int img_commit(int argc, char **argv)
         .bs   = bs,
     };
 
-    commit_active_start(NULL, bs, base_bs, 0, BLOCKDEV_ON_ERROR_REPORT,
+    commit_active_start("commit", bs, base_bs, 0, BLOCKDEV_ON_ERROR_REPORT,
                         common_block_job_cb, &cbi, &local_err);
     if (local_err) {
         goto done;