block: refactor bdrv_reopen_commit

Add bs local variable to simplify code.
Signed-off-by: NVladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: NJohn Snow <jsnow@redhat.com>
Message-id: 20170628120530.31251-13-vsementsov@virtuozzo.com
Signed-off-by: NMax Reitz <mreitz@redhat.com>

block.c

@@ -2982,9 +2982,11 @@ error:
 void bdrv_reopen_commit(BDRVReopenState *reopen_state)
 {
     BlockDriver *drv;
+    BlockDriverState *bs;
 
     assert(reopen_state != NULL);
-    drv = reopen_state->bs->drv;
+    bs = reopen_state->bs;
+    drv = bs->drv;
     assert(drv != NULL);
 
     /* If there are any driver level actions to take */
@@ -2993,13 +2995,13 @@ void bdrv_reopen_commit(BDRVReopenState *reopen_state)
     }
 
     /* set BDS specific flags now */
-    QDECREF(reopen_state->bs->explicit_options);
+    QDECREF(bs->explicit_options);
 
-    reopen_state->bs->explicit_options   = reopen_state->explicit_options;
-    reopen_state->bs->open_flags         = reopen_state->flags;
-    reopen_state->bs->read_only = !(reopen_state->flags & BDRV_O_RDWR);
+    bs->explicit_options   = reopen_state->explicit_options;
+    bs->open_flags         = reopen_state->flags;
+    bs->read_only = !(reopen_state->flags & BDRV_O_RDWR);
 
-    bdrv_refresh_limits(reopen_state->bs, NULL);
+    bdrv_refresh_limits(bs, NULL);
 }
 
 /*