gfs2: Lock holder cleanup

Make the code more readable by cleaning up the different ways of
initializing lock holders and checking for initialized lock holders:
mark lock holders as uninitialized by setting the holder's glock to NULL
(gfs2_holder_mark_uninitialized) instead of zeroing out the entire
object or using a separate flag.  Recognize initialized holders by their
non-NULL glock (gfs2_holder_initialized).  Don't zero out holder objects
which are immeditiately initialized via gfs2_holder_init or
gfs2_glock_nq_init.

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

fs/gfs2/quota.c

@@ -883,7 +883,7 @@ static int do_sync(unsigned int num_qd, struct gfs2_quota_data **qda)
 	gfs2_write_calc_reserv(ip, sizeof(struct gfs2_quota),
 			      &data_blocks, &ind_blocks);
 
-	ghs = kcalloc(num_qd, sizeof(struct gfs2_holder), GFP_NOFS);
+	ghs = kmalloc(num_qd * sizeof(struct gfs2_holder), GFP_NOFS);
 	if (!ghs)
 		return -ENOMEM;