Remove dead code: jniGetStackTrace.

Change-Id: I841da6eef183ddf13a9c058c204f4f244a389eb3
diff --git a/JNIHelp.cpp b/JNIHelp.cpp
index 4b77680..7fc166a 100644
--- a/JNIHelp.cpp
+++ b/JNIHelp.cpp
@@ -256,12 +256,7 @@
     return jniThrowException(env, "java/io/IOException", message);
 }
 
-void jniLogException(C_JNIEnv* env, int priority, const char* tag, jthrowable exception) {
-    std::string trace(jniGetStackTrace(env, exception));
-    __android_log_write(priority, tag, trace.c_str());
-}
-
-extern "C" std::string jniGetStackTrace(C_JNIEnv* env, jthrowable exception) {
+static std::string jniGetStackTrace(C_JNIEnv* env, jthrowable exception) {
     JNIEnv* e = reinterpret_cast<JNIEnv*>(env);
 
     scoped_local_ref<jthrowable> currentException(env, (*env)->ExceptionOccurred(e));
@@ -289,6 +284,11 @@
     return trace;
 }
 
+void jniLogException(C_JNIEnv* env, int priority, const char* tag, jthrowable exception) {
+    std::string trace(jniGetStackTrace(env, exception));
+    __android_log_write(priority, tag, trace.c_str());
+}
+
 const char* jniStrError(int errnum, char* buf, size_t buflen) {
     // Note: glibc has a nonstandard strerror_r that returns char* rather than POSIX's int.
     // char *strerror_r(int errnum, char *buf, size_t n);