GFS2: Don't try to end a non-existent transaction in unlink

Before this patch, if function gfs2_unlink failed to get a valid
transaction (for example, not enough journal blocks) it would go
to label out_end_trans which did gfs2_trans_end. But if the
trans_begin failed, there's no transaction to end, and trying to
do so results in: kernel BUG at fs/gfs2/trans.c:117!

This patch changes the goto so that it does not try to end a
non-existent transaction.
Signed-off-by: Bob Peterson <rpeterso@redhat.com>

fs/gfs2/inode.c

@@ -1152,12 +1152,11 @@ static int gfs2_unlink(struct inode *dir, struct dentry *dentry)
 
 	error = gfs2_trans_begin(sdp, 2*RES_DINODE + 3*RES_LEAF + RES_RG_BIT, 0);
 	if (error)
-		goto out_end_trans;
+		goto out_gunlock;
 
 	error = gfs2_unlink_inode(dip, dentry);
-
-out_end_trans:
 	gfs2_trans_end(sdp);
+
 out_gunlock:
 	gfs2_glock_dq(ghs + 2);
 out_rgrp: