Fixing some of the issues found by clang static analyzer.

Bug: webrtc:8737
Change-Id: Ib436449c493336e7c35a72a96dc88cccdbb5bbaf
Reviewed-on: https://webrtc-review.googlesource.com/39200
Commit-Queue: Peter Hanspers <peterhanspers@webrtc.org>
Reviewed-by: Henrik Andreassson <henrika@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#21607}
diff --git a/sdk/objc/Framework/Classes/PeerConnection/RTCFileVideoCapturer.m b/sdk/objc/Framework/Classes/PeerConnection/RTCFileVideoCapturer.m
index 07cb2c6..7e27bf2 100644
--- a/sdk/objc/Framework/Classes/PeerConnection/RTCFileVideoCapturer.m
+++ b/sdk/objc/Framework/Classes/PeerConnection/RTCFileVideoCapturer.m
@@ -139,6 +139,7 @@
   }
   if (CMSampleBufferGetNumSamples(sampleBuffer) != 1 || !CMSampleBufferIsValid(sampleBuffer) ||
       !CMSampleBufferDataIsReady(sampleBuffer)) {
+    CFRelease(sampleBuffer);
     [self readNextBuffer];
     return;
   }