lmLogOpen() broken failure exit

Callers of lmLogOpen() expect it to return -E... on failure exits, which
is what it returns, except for the case of blkdev_get_by_dev() failure.
It that case lmLogOpen() return the error with the wrong sign...
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>
Acked-by: NDave Kleikamp <dave.kleikamp@oracle.com>

fs/jfs/jfs_logmgr.c

@@ -1123,7 +1123,7 @@ int lmLogOpen(struct super_block *sb)
 	bdev = blkdev_get_by_dev(sbi->logdev, FMODE_READ|FMODE_WRITE|FMODE_EXCL,
 				 log);
 	if (IS_ERR(bdev)) {
-		rc = -PTR_ERR(bdev);
+		rc = PTR_ERR(bdev);
 		goto free;
 	}