coreinfo: Use regular `if` over `#if` for `IS_ENABLED`

When using the regular `if` construct, the compiler will check
the guarded code independently from the condition.

Change-Id: I00c5c7ae3720f75aa9415edb94cd2ce76cee8aee
Signed-off-by: Nicola Corna <nicola@corna.info>
Reviewed-on: https://review.coreboot.org/18811
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Martin Roth <martinroth@google.com>

payloads/coreinfo/coreinfo.c

@@ -291,9 +291,8 @@ int main(void)
 {
 	int i, j;
 
-#if IS_ENABLED(CONFIG_LP_USB)
-	usb_initialize();
-#endif
+	if (IS_ENABLED(CONFIG_LP_USB))
+		usb_initialize();
 
 	initscr();