[media] tw5864-core: remove excessive irqsave

As warned by smatch:
	drivers/media/pci/tw5864/tw5864-core.c:160 tw5864_h264_isr() error: double lock 'irqsave:flags'
	drivers/media/pci/tw5864/tw5864-core.c:174 tw5864_h264_isr() error: double unlock 'irqsave:flags'

Two different spinlocks are obtained, so having two calls is correct,
but second irqsave is superfluous, and using same "flags" variable is
just wrong.
Reported-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
Signed-off-by: Andrey Utkin <andrey.utkin@corp.bluecherry.net>
Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>

drivers/media/pci/tw5864/tw5864-core.c

@@ -157,12 +157,12 @@ static void tw5864_h264_isr(struct tw5864_dev *dev)
 
 		cur_frame = next_frame;
 
-		spin_lock_irqsave(&input->slock, flags);
+		spin_lock(&input->slock);
 		input->frame_seqno++;
 		input->frame_gop_seqno++;
 		if (input->frame_gop_seqno >= input->gop)
 			input->frame_gop_seqno = 0;
-		spin_unlock_irqrestore(&input->slock, flags);
+		spin_unlock(&input->slock);
 	} else {
 		dev_err(&dev->pci->dev,
 			"Skipped frame on input %d because all buffers busy\n",