gfs2: Fix "gfs2: Switch to wait_event in gfs2_quotad"

Commit e4a8b54 ("gfs2: Switch to wait_event in gfs2_quotad") broke
cyclic statfs syncing, so the numbers reported by "df" could easily get
completely out of sync with reality.  Fix this by reverting part of
commit e4a8b54 for now.

A follow-up commit will clean this code up later.

Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>

Author: Andreas Gruenbacher

fs/gfs2/quota.c

@@ -1616,7 +1616,7 @@ int gfs2_quotad(void *data)
 
 		t = min(quotad_timeo, statfs_timeo);
 
-		t = wait_event_freezable_timeout(sdp->sd_quota_wait,
+		t -= wait_event_freezable_timeout(sdp->sd_quota_wait,
 				sdp->sd_statfs_force_sync ||
 				gfs2_withdrawing_or_withdrawn(sdp) ||
 				kthread_should_stop(),