ntb_hw_switchtec: Fix another ntb_mw_clear_trans error if size == 0

ntb_mw_set_trans() should work as ntb_mw_clear_trans() when size == 0 and/or
addr == 0. Check alignment only when size is not zero.

Author: kelvin-cao

ntb_hw_switchtec.c

@@ -383,7 +383,7 @@ static int switchtec_ntb_mw_set_trans(struct ntb_dev *ntb, int pidx, int widx,
 	if (size != 0 && xlate_pos < 12)
 		return -EINVAL;
 
-	if (!IS_ALIGNED(addr, BIT_ULL(xlate_pos))) {
+	if (size != 0 && !IS_ALIGNED(addr, BIT_ULL(xlate_pos))) {
 		/*
 		 * In certain circumstances we can get a buffer that is
 		 * not aligned to its size. (Most of the time