ocfs2: remove handle argument to ocfs2_start_trans()

All callers either pass in NULL directly, or a local variable that is
already set to NULL.

The internals of ocfs2_start_trans() get a nice cleanup as a result.

Signed-off-by: Mark Fasheh <mark.fasheh@oracle.com>

fs/ocfs2/suballoc.c

@@ -302,7 +302,7 @@ static int ocfs2_block_group_alloc(struct ocfs2_super *osb,
 
 	credits = ocfs2_calc_group_alloc_credits(osb->sb,
 						 le16_to_cpu(cl->cl_cpg));
-	handle = ocfs2_start_trans(osb, handle, credits);
+	handle = ocfs2_start_trans(osb, credits);
 	if (IS_ERR(handle)) {
 		status = PTR_ERR(handle);
 		handle = NULL;