Fix nullptr check

We assume the function argument is non-null (otherwise we would
have crashed by this point).  What we really want to check here
is the result of the subfunction we've called, so we fix the
code to do that.

Test: TreeHugger
Bug: 190810951
Change-Id: I4f979c98f90b772527b270d51a25dcbfd8b122a2

core/jni/android_media_AudioSystem.cpp

@@ -1288,7 +1288,7 @@ static jint convertAudioProfileFromNative(JNIEnv *env, jobject *jAudioProfile,
                            audioFormatFromNative(nAudioProfile->format), jSamplingRates.get(),
                            jChannelMasks.get(), jChannelIndexMasks.get(), encapsulationType);
 
-    if (jAudioProfile == nullptr) {
+    if (*jAudioProfile == nullptr) {
         return AUDIO_JAVA_ERROR;
     }