SCM: Use std::string.

Those macros may be defined, or not. We should support both cases, so use std::string as it also defines the length of the string.

Source/Android/jni/MainAndroid.cpp

@@ -475,7 +475,7 @@ JNIEXPORT jint JNICALL Java_org_dolphinemu_dolphinemu_NativeLibrary_GetPlatform(
 
 JNIEXPORT jstring JNICALL Java_org_dolphinemu_dolphinemu_NativeLibrary_GetVersionString(JNIEnv *env, jobject obj)
 {
-	return env->NewStringUTF(scm_rev_str);
+	return env->NewStringUTF(scm_rev_str.c_str());
 }
 
 JNIEXPORT jboolean JNICALL Java_org_dolphinemu_dolphinemu_NativeLibrary_SupportsNEON(JNIEnv *env, jobject obj)