Use mFrameSize instead of mBitShift

Change-Id: Idac335ae70cc9300bb3325839fe8ef1e9e097245
diff --git a/media/libnbaio/MonoPipe.cpp b/media/libnbaio/MonoPipe.cpp
index b23967b..9c8461c 100644
--- a/media/libnbaio/MonoPipe.cpp
+++ b/media/libnbaio/MonoPipe.cpp
@@ -115,11 +115,11 @@
             part1 = written;
         }
         if (CC_LIKELY(part1 > 0)) {
-            memcpy((char *) mBuffer + (rear << mBitShift), buffer, part1 << mBitShift);
+            memcpy((char *) mBuffer + (rear * mFrameSize), buffer, part1 * mFrameSize);
             if (CC_UNLIKELY(rear + part1 == mMaxFrames)) {
                 size_t part2 = written - part1;
                 if (CC_LIKELY(part2 > 0)) {
-                    memcpy(mBuffer, (char *) buffer + (part1 << mBitShift), part2 << mBitShift);
+                    memcpy(mBuffer, (char *) buffer + (part1 * mFrameSize), part2 * mFrameSize);
                 }
             }
             android_atomic_release_store(written + mRear, &mRear);
@@ -129,7 +129,7 @@
             break;
         }
         count -= written;
-        buffer = (char *) buffer + (written << mBitShift);
+        buffer = (char *) buffer + (written * mFrameSize);
         // Simulate blocking I/O by sleeping at different rates, depending on a throttle.
         // The throttle tries to keep the mean pipe depth near the setpoint, with a slight jitter.
         uint32_t ns;