Fix divide by zero exception with default sampleRate of 0

Bug: 27827281
Change-Id: I6cd03712c64bee3582ba0c5be7d5d3035c4861c1
diff --git a/media/libmedia/AudioRecord.cpp b/media/libmedia/AudioRecord.cpp
index 79ce75e..e0368ed 100644
--- a/media/libmedia/AudioRecord.cpp
+++ b/media/libmedia/AudioRecord.cpp
@@ -271,7 +271,7 @@
     mActive = false;
     mUserData = user;
     // TODO: add audio hardware input latency here
-    mLatency = (1000*mFrameCount) / sampleRate;
+    mLatency = (1000 * mFrameCount) / mSampleRate;
     mMarkerPosition = 0;
     mMarkerReached = false;
     mNewPosition = 0;