media: em28xx: make v4l2-compliance happier by starting sequence on zero

commit afeaade9 upstream.

The v4l2-compliance tool complains if a video doesn't start
with a zero sequence number.

While this shouldn't cause any real problem for apps, let's
make it happier, in order to better check the v4l2-compliance
differences before and after patchsets.

This is actually an old issue. It is there since at least its
videobuf2 conversion, e. g. changeset 3829fadc461 ("[media]
em28xx: convert to videobuf2"), if VB1 wouldn't suffer from
the same issue.

Cc: stable@vger.kernel.org
Fixes: d3829fad ("[media] em28xx: convert to videobuf2")
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/media/usb/em28xx/em28xx-video.c

@@ -900,6 +900,8 @@ static int em28xx_enable_analog_tuner(struct em28xx *dev)
 	if (!mdev || !v4l2->decoder)
 		return 0;
 
+	dev->v4l2->field_count = 0;
+
 	/*
 	 * This will find the tuner that is connected into the decoder.
 	 * Technically, this is not 100% correct, as the device may be