net: mscc: simplify retrieving the tag type from the frame header

The tag type in the frame extraction header is only a bit wide. There's
no need to use GENMASK when retrieving the information. This patch
simplify the code by dropping GENMASK and using BIT instead.
Signed-off-by: NAntoine Tenart <antoine.tenart@bootlin.com>
Reviewed-by: NAlexandre Belloni <alexandre.belloni@bootlin.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

drivers/net/ethernet/mscc/ocelot_board.c

@@ -29,7 +29,7 @@ static int ocelot_parse_ifh(u32 *ifh, struct frame_info *info)
 	info->port = (ifh[2] & GENMASK(14, 11)) >> 11;
 
 	info->cpuq = (ifh[3] & GENMASK(27, 20)) >> 20;
-	info->tag_type = (ifh[3] & GENMASK(16, 16)) >> 16;
+	info->tag_type = (ifh[3] & BIT(16)) >> 16;
 	info->vid = ifh[3] & GENMASK(11, 0);
 
 	return 0;