ec/google: Fix bad return value

google_chromeec_get_event returns an event number and 0 when there's no event.
This function is usually called in a loop until there are no more events, so
it makes sense to return 0 (i.e. no event) when there's an error.

BUG=b:184074997
TEST=Boot guybrush, no ec errors

Change-Id: I6c0186e4637af9ae24f45cce3638f0913227d6a7
Signed-off-by: Rob Barnes <robbarnes@google.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/55437
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Raul Rangel <rrangel@chromium.org>
Reviewed-by: Angel Pons <th3fanbus@gmail.com>

src/ec/google/chromeec/ec_lpc.c

@@ -465,7 +465,7 @@ u8 google_chromeec_get_event(void)
 {
 	if (google_chromeec_wait_ready(EC_LPC_ADDR_ACPI_CMD)) {
 		printk(BIOS_ERR, "Timeout waiting for EC ready!\n");
-		return 1;
+		return 0;
 	}
 
 	/* Issue the ACPI query-event command */