[media] via-camera: simplify boolean tests

Instead of using if (foo == false), just use
if (!foo).

That allows a faster mental parsing when analyzing the
code.
Signed-off-by: Mauro Carvalho Chehab <m.chehab@samsung.com>

drivers/media/platform/via-camera.c

@@ -1276,7 +1276,7 @@ static bool viacam_serial_is_enabled(void)
 			VIACAM_SERIAL_CREG, &cbyte);
 	if ((cbyte & VIACAM_SERIAL_BIT) == 0)
 		return false; /* Not enabled */
-	if (override_serial == 0) {
+	if (!override_serial) {
 		printk(KERN_NOTICE "Via camera: serial port is enabled, " \
 				"refusing to load.\n");
 		printk(KERN_NOTICE "Specify override_serial=1 to force " \