jfs: Fix memleak in dbAdjCtl

When dbBackSplit() fails, mp should be released to
prevent memleak. It's the same when dbJoin() fails.

Signed-off-by: Dinghao Liu <dinghao.liu@zju.edu.cn>
Signed-off-by: Dave Kleikamp <dave.kleikamp@oracle.com>

fs/jfs/jfs_dmap.c

@@ -2549,15 +2549,19 @@ dbAdjCtl(struct bmap * bmp, s64 blkno, int newval, int alloc, int level)
 		 */
 		if (oldval == NOFREE) {
 			rc = dbBackSplit((dmtree_t *) dcp, leafno);
-			if (rc)
+			if (rc) {
+				release_metapage(mp);
 				return rc;
+			}
 			oldval = dcp->stree[ti];
 		}
 		dbSplit((dmtree_t *) dcp, leafno, dcp->budmin, newval);
 	} else {
 		rc = dbJoin((dmtree_t *) dcp, leafno, newval);
-		if (rc)
+		if (rc) {
+			release_metapage(mp);
 			return rc;
+		}
 	}
 
 	/* check if the root of the current dmap control page changed due