codecs: check OMX buffer size before use in VP8 encoder.

Bug: 27569635
Change-Id: I469573f40e21dc9f4c200749d4f220e3a2d31761

status_t SoftVPXEncoder::releaseEncoder() {
 if (mCodecContext != NULL) {
        vpx_codec_destroy(mCodecContext);
 delete mCodecContext;
        mCodecContext = NULL;
 }

 if (mCodecConfiguration != NULL) {
 delete mCodecConfiguration;
        mCodecConfiguration = NULL;
 }

 if (mConversionBuffer != NULL) {
        free(mConversionBuffer);
        mConversionBuffer = NULL;
 }

    mCodecInterface = NULL;

 return OK;
}

status_t SoftVPXEncoder::releaseEncoder() {
 if (mCodecContext != NULL) {
        vpx_codec_destroy(mCodecContext);
 delete mCodecContext;
        mCodecContext = NULL;
 }

 if (mCodecConfiguration != NULL) {
 delete mCodecConfiguration;
        mCodecConfiguration = NULL;
 }

 if (mConversionBuffer != NULL) {
        free(mConversionBuffer);
        mConversionBuffer = NULL;
 }

    mCodecInterface = NULL;

 return OK;
}
