Rename Visualizer::mLock

This avoids confusion with parent class AudioEffect's mLock which is
protected.

Change-Id: I2ae0b0869fe3c606f682252973795b34477951d0
diff --git a/media/libmedia/Visualizer.cpp b/media/libmedia/Visualizer.cpp
index 66758d2..dba257d 100644
--- a/media/libmedia/Visualizer.cpp
+++ b/media/libmedia/Visualizer.cpp
@@ -54,7 +54,7 @@
 
 status_t Visualizer::setEnabled(bool enabled)
 {
-    Mutex::Autolock _l(mLock);
+    Mutex::Autolock _l(mCaptureLock);
 
     sp<CaptureThread> t = mCaptureThread;
     if (t != 0) {
@@ -93,7 +93,7 @@
     if (rate > CAPTURE_RATE_MAX) {
         return BAD_VALUE;
     }
-    Mutex::Autolock _l(mLock);
+    Mutex::Autolock _l(mCaptureLock);
 
     if (mEnabled) {
         return INVALID_OPERATION;
@@ -129,7 +129,7 @@
         return BAD_VALUE;
     }
 
-    Mutex::Autolock _l(mLock);
+    Mutex::Autolock _l(mCaptureLock);
     if (mEnabled) {
         return INVALID_OPERATION;
     }
@@ -231,7 +231,7 @@
 
 void Visualizer::periodicCapture()
 {
-    Mutex::Autolock _l(mLock);
+    Mutex::Autolock _l(mCaptureLock);
     ALOGV("periodicCapture() %p mCaptureCallBack %p mCaptureFlags 0x%08x",
             this, mCaptureCallBack, mCaptureFlags);
     if (mCaptureCallBack != NULL &&