[media] tm6000: Fix a warning at tm6000_ir_int_start()

drivers/media/video/tm6000/tm6000-input.c: In function ‘tm6000_ir_int_start’:
drivers/media/video/tm6000/tm6000-input.c:381:3: warning: ‘return’ with no value, in function returning non-void [-Wreturn-type]
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>

drivers/media/video/tm6000/tm6000-input.c

@@ -378,7 +378,7 @@ int tm6000_ir_int_start(struct tm6000_core *dev)
 	struct tm6000_IR *ir = dev->ir;
 
 	if (!ir)
-		return;
+		return 0;
 
 	return __tm6000_ir_int_start(ir->rc);
 }