libpayload: code cosmetics

Be consistend with coding style at least within a function -- don't mix
sizeof with plain values.

Change-Id: Iefb5b7fe4f54977f5505fc9cea65c9c4af3e7f3a
Signed-off-by: Mathias Krause <mathias.krause@secunet.com>
Reviewed-on: http://review.coreboot.org/617
Tested-by: build bot (Jenkins)
Reviewed-by: Stefan Reinauer <stefan.reinauer@coreboot.org>

payloads/libpayload/drivers/options.c

@@ -309,7 +309,7 @@ int set_option_from_string(const struct nvram_accessor *nvram, struct cb_cmos_op
 	switch (cmos_entry->config) {
 		case 'h':
 			/* only works on little endian */
-			raw = malloc(8);
+			raw = malloc(sizeof(u64));
 			*(u64*)raw = strtoull(value, NULL, 0);
 			break;
 		case 's':