msm: camera: fix error check in msm vb2.

The return value from the get stream function could be
an error pointer. Hence, it is not sufficient to do a
NULL check on the return value. Instead we need to pass
the pointer through the IS_ERR_OR_NULL function.

Change-Id: I32afbbc53a3b67cc75472db56173f640e9c398e3
Signed-off-by: Ankit Premrajka <ankitp@codeaurora.org>
diff --git a/drivers/media/platform/msm/camera_v2/msm_vb2/msm_vb2.c b/drivers/media/platform/msm/camera_v2/msm_vb2/msm_vb2.c
index 6ea86ae..6e99c92 100644
--- a/drivers/media/platform/msm/camera_v2/msm_vb2/msm_vb2.c
+++ b/drivers/media/platform/msm/camera_v2/msm_vb2/msm_vb2.c
@@ -105,7 +105,7 @@
 	unsigned long flags;
 
 	stream = msm_get_stream(session_id, stream_id);
-	if (!stream)
+	if (IS_ERR_OR_NULL(stream))
 		return NULL;
 
 	spin_lock_irqsave(&stream->stream_lock, flags);
@@ -163,7 +163,7 @@
 	int rc = 0;
 
 	stream = msm_get_stream(session_id, stream_id);
-	if (!stream)
+	if (IS_ERR_OR_NULL(stream))
 		return 0;
 	spin_lock_irqsave(&stream->stream_lock, flags);
 	if (vb) {