[media] xc4000: Fix a few warnings

drivers/media/tuners/xc4000.c: In function ‘check_firmware’:
drivers/media/tuners/xc4000.c:1048:45: warning: ‘fw_minor’ may be used uninitialized in this function [-Wmaybe-uninitialized]
drivers/media/tuners/xc4000.c:1048:39: warning: ‘fw_major’ may be used uninitialized in this function [-Wmaybe-uninitialized]
drivers/media/tuners/xc4000.c:1062:39: warning: ‘hw_minor’ may be used uninitialized in this function [-Wmaybe-uninitialized]
drivers/media/tuners/xc4000.c:1062:33: warning: ‘hw_major’ may be used uninitialized in this function [-Wmaybe-uninitialized]

Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
diff --git a/drivers/media/tuners/xc4000.c b/drivers/media/tuners/xc4000.c
index 4937712..5c0fd78 100644
--- a/drivers/media/tuners/xc4000.c
+++ b/drivers/media/tuners/xc4000.c
@@ -934,7 +934,7 @@
 	int			   rc = 0, is_retry = 0;
 	u16			   hwmodel;
 	v4l2_std_id		   std0;
-	u8			   hw_major, hw_minor, fw_major, fw_minor;
+	u8			   hw_major = 0, hw_minor = 0, fw_major = 0, fw_minor = 0;
 
 	dprintk(1, "%s called\n", __func__);