libstagefright: remove out of date profiling result before doing a new profiling.

// static

void *MediaCodecList::profilerThreadWrapper(void * /*arg*/) {

    ALOGV("Enter profilerThreadWrapper.");

    remove(kProfilingResults);  // remove previous result so that it won't be loaded to

                                // the new MediaCodecList

    MediaCodecList *codecList = new MediaCodecList();

    if (codecList->initCheck() != OK) {

        ALOGW("Failed to create a new MediaCodecList, skipping codec profiling.");