xfs: free bp in xlog_find_zeroed() error path

xlog_find_zeroed() currently leaks a bp on one error path.

Using the bp_err: target resolves this.

Found by Coverity.
Signed-off-by: NEric Sandeen <sandeen@redhat.com>
Reviewed-by: NMark Tinguely <tinguely@sgi.com>
Signed-off-by: NBen Myers <bpm@sgi.com>

fs/xfs/xfs_log_recover.c

@@ -1145,7 +1145,8 @@ xlog_find_zeroed(
 		 */
 		xfs_warn(log->l_mp,
 			"Log inconsistent or not a log (last==0, first!=1)");
-		return XFS_ERROR(EINVAL);
+		error = XFS_ERROR(EINVAL);
+		goto bp_err;
 	}
 
 	/* we have a partially zeroed log */