GFS2: fix s_writers.counter imbalance in gfs2_ail_empty_gl

gfs2_ail_empty_gl() contains an "inline version" of gfs2_trans_begin(),
so it needs an explicit sb_start_intwrite() as well, to balance the
sb_end_intwrite() which will be called by gfs2_trans_end().

With this, xfstest 068 passes on lock_nolock local gfs2.
Without it, we reach a writer count of -1 and get stuck.

Signed-off-by: Eric Sandeen <sandeen@redhat.com>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
diff --git a/fs/gfs2/glops.c b/fs/gfs2/glops.c
index 4bdcf37..32cc4fd 100644
--- a/fs/gfs2/glops.c
+++ b/fs/gfs2/glops.c
@@ -94,6 +94,7 @@
 	/* A shortened, inline version of gfs2_trans_begin() */
 	tr.tr_reserved = 1 + gfs2_struct2blk(sdp, tr.tr_revokes, sizeof(u64));
 	tr.tr_ip = (unsigned long)__builtin_return_address(0);
+	sb_start_intwrite(sdp->sd_vfs);
 	gfs2_log_reserve(sdp, tr.tr_reserved);
 	BUG_ON(current->journal_info);
 	current->journal_info = &tr;