[media] coda: free context buffers under buffer mutex

Make sure the buffer_mutex lock is taken in coda_bit_release
while coda_free_framebuffers and coda_free_context_buffers
are called.

Signed-off-by: Philipp Zabel <p.zabel@pengutronix.de>
Signed-off-by: Kamil Debski <k.debski@samsung.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com>

drivers/media/platform/coda/coda-bit.c

@@ -1319,8 +1319,10 @@ static void coda_seq_end_work(struct work_struct *work)
 
 static void coda_bit_release(struct coda_ctx *ctx)
 {
+	mutex_lock(&ctx->buffer_mutex);
 	coda_free_framebuffers(ctx);
 	coda_free_context_buffers(ctx);
+	mutex_unlock(&ctx->buffer_mutex);
 }
 
 const struct coda_context_ops coda_bit_encode_ops = {