Remove JNI_FORCE_C

This hasn't been useful in a really long time.

Change-Id: Ieea01f5d051bc8fc671f7414af3bed626ece75f1
diff --git a/libnativehelper/include/nativehelper/JNIHelp.h b/libnativehelper/include/nativehelper/JNIHelp.h
index 1c9f933..71ecf38 100644
--- a/libnativehelper/include/nativehelper/JNIHelp.h
+++ b/libnativehelper/include/nativehelper/JNIHelp.h
@@ -106,7 +106,7 @@
  * For C++ code, we provide inlines that map to the C functions.  g++ always
  * inlines these, even on non-optimized builds.
  */
-#if defined(__cplusplus) && !defined(JNI_FORCE_C)
+#if defined(__cplusplus)
 inline int jniRegisterNativeMethods(JNIEnv* env, const char* className,
     const JNINativeMethod* gMethods, int numMethods)
 {