s390: Fix possibly wrong size in strncmp (smsgiucv)

This error was reported by cppcheck:
drivers/s390/net/smsgiucv.c:63: error: Using sizeof for array given as
function argument returns the size of pointer.

Although there is no runtime problem as long as sizeof(u8 *) == 8,
this misleading code should get fixed.
Signed-off-by: Stefan Weil <weil@mail.berlios.de>
Signed-off-by: Frank Blaschka <frank.blaschka@de.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/s390/net/smsgiucv.c

@@ -60,7 +60,7 @@ static struct iucv_handler smsg_handler = {
 static int smsg_path_pending(struct iucv_path *path, u8 ipvmid[8],
 			     u8 ipuser[16])
 {
-	if (strncmp(ipvmid, "*MSG    ", sizeof(ipvmid)) != 0)
+	if (strncmp(ipvmid, "*MSG    ", 8) != 0)
 		return -EINVAL;
 	/* Path pending from *MSG. */
 	return iucv_path_accept(path, &smsg_handler, "SMSGIUCV        ", NULL);