net/sfc/base: fix shift by more bits than field width

This was probably an oversight when support for multiple sensor pages
was added.

Despite being undefined behaviour in C, it probably worked on Intel
x32/x64 as on them bit shift operations wrap round.

Fixes: dfb3b1ce15 ("net/sfc/base: import monitors access via MCDI")
Cc: stable@dpdk.org

Signed-off-by: Mark Spender <mspender@solarflare.com>
Signed-off-by: Andrew Rybchenko <arybchenko@solarflare.com>

drivers/net/sfc/base/mcdi_mon.c

@@ -73,7 +73,8 @@ mcdi_mon_decode_stats(
 			/* This sensor is one of the page boundary bits. */
 		}
 
-		if (~(sensor_mask[page]) & (1U << sensor))
+		if (~(sensor_mask[page]) &
+		    (1U << (sensor % (sizeof (sensor_mask[page]) * 8))))
 			continue;
 		/* This sensor not in DMA buffer */