gnss: sirf: fix activation retry handling

Fix activation helper which would return -ETIMEDOUT even if the last
retry attempt was successful.

Also change the semantics of the retries variable so that it actually
holds the number of retries (rather than tries).

Fixes: d2efbbd ("gnss: add driver for sirfstar-based receivers")
Cc: stable <stable@vger.kernel.org>	# 4.19
Signed-off-by: Johan Hovold <johan@kernel.org>

drivers/gnss/sirf.c

@@ -168,7 +168,7 @@ static int sirf_set_active(struct sirf_data *data, bool active)
 	else
 		timeout = SIRF_HIBERNATE_TIMEOUT;
 
-	while (retries-- > 0) {
+	do {
 		sirf_pulse_on_off(data);
 		ret = sirf_wait_for_power_state(data, active, timeout);
 		if (ret < 0) {
@@ -179,9 +179,9 @@ static int sirf_set_active(struct sirf_data *data, bool active)
 		}
 
 		break;
-	}
+	} while (retries--);
 
-	if (retries == 0)
+	if (retries < 0)
 		return -ETIMEDOUT;
 
 	return 0;