ice: use flex_array_size where possible

Use the flex_array_size() helper with the recently added flexible array
members in structures.
Signed-off-by: Bruce Allan <bruce.w.allan@intel.com>
Tested-by: Tony Brelinski <tonyx.brelinski@intel.com>
Signed-off-by: Tony Nguyen <anthony.l.nguyen@intel.com>

drivers/net/ethernet/intel/ice/ice_common.c

@@ -1653,7 +1653,7 @@ ice_aq_alloc_free_res(struct ice_hw *hw, u16 num_entries,
 	if (!buf)
 		return ICE_ERR_PARAM;
 
-	if (buf_size < (num_entries * sizeof(buf->elem[0])))
+	if (buf_size < flex_array_size(buf, elem, num_entries))
 		return ICE_ERR_PARAM;
 
 	ice_fill_dflt_direct_cmd_desc(&desc, opc);

drivers/net/ethernet/intel/ice/ice_flex_pipe.c

@@ -1525,7 +1525,7 @@ ice_pkg_buf_reserve_section(struct ice_buf_build *bld, u16 count)
 	bld->reserved_section_table_entries += count;
 
 	data_end = le16_to_cpu(buf->data_end) +
-		   (count * sizeof(buf->section_entry[0]));
+		flex_array_size(buf, section_entry, count);
 	buf->data_end = cpu_to_le16(data_end);
 
 	return 0;