Better arg checking for reboot command

Allows 'reboot cold' as an alias for 'reboot hard', since I keep
mis-typing that anyway.  Returns error for any other option.
('reboot' by itself still does a warm reboot).

BUG=none
TEST=manual

reboot -> does warm reboot
reboot hard -> does hard reboot (reason = rtc alarm)
reboot cold -> ditto
reboot foo -> prints error

Change-Id: I183714d4ba09abee3bd9a6f0d5df82389becf410
Signed-off-by: Randall Spangler <rspangler@chromium.org>
Reviewed-on: https://gerrit.chromium.org/gerrit/26924

common/system_common.c

@@ -652,9 +652,13 @@ static int command_reboot(int argc, char **argv)
 {
 	int is_hard = 0;
 
-	if (argc == 2 && !strcasecmp(argv[1], "hard")) {
-		ccputs("Hard-");
-		is_hard = 1;
+	if (argc == 2) {
+		if (!strcasecmp(argv[1], "hard") ||
+		    !strcasecmp(argv[1], "cold")) {
+			ccputs("Hard-");
+			is_hard = 1;
+		} else
+			return EC_ERROR_PARAM1;
 	}
 
 	ccputs("Rebooting!\n\n\n");