RegisterNatives() returns 0 on success.

cf. http://docs.oracle.com/javase/6/docs/technotes/guides/jni/spec/functions.html#wp5833

Change-Id: I2c599f2d8765a7475c7076e6b049f77ad79feb79
diff --git a/native/jni/jni_common.cpp b/native/jni/jni_common.cpp
index 9fa7ef8..ce5e30c 100644
--- a/native/jni/jni_common.cpp
+++ b/native/jni/jni_common.cpp
@@ -67,7 +67,7 @@
         AKLOGE("Native registration unable to find class '%s'", className);
         return JNI_FALSE;
     }
-    if (env->RegisterNatives(clazz, methods, numMethods) < 0) {
+    if (env->RegisterNatives(clazz, methods, numMethods) != 0) {
         AKLOGE("RegisterNatives failed for '%s'", className);
         env->DeleteLocalRef(clazz);
         return JNI_FALSE;