Don't re-use arttest when calling loadLibrary.

When Android's build environment variables are set with envsetup.sh,
the test "works" ok, by getting a LinkageError because two class loaders
try to load the same library. I guess that is the reason for the
if (ExceptionCheck()) after the loading.

However, if the environment variables are set manually, there are
cases where the paths provided between a Java loadLibrary, and a
native loadLibrary are different, so we end up loading the library twice.
This makes the assertion line 32 fail on the second JNI_OnLoad call.
In my particular environment, ANDROID_BUILD_TOP was something lie
/foo/bar/..//.

This change stops re-using the same library, and makes the expected
outcome constant: the native call of loadLibrary with a non exist
library must throw a LinkageError.

Change-Id: I8721a03715e099c55fb8b2b87813f1e772c8e83d
diff --git a/test/004-JniTest/jni_test.cc b/test/004-JniTest/jni_test.cc
index c2877be..544cbc5 100644
--- a/test/004-JniTest/jni_test.cc
+++ b/test/004-JniTest/jni_test.cc
@@ -294,20 +294,20 @@
     assert(!env->ExceptionCheck());
 
     // Create a string object.
-    jobject library_string = env->NewStringUTF("arttest");
+    jobject library_string = env->NewStringUTF("non_existing_library");
     assert(library_string != nullptr);
     assert(!env->ExceptionCheck());
 
     env->CallStaticVoidMethod(system_clazz, loadLibraryMethodId, library_string);
-    if (env->ExceptionCheck()) {
-      // At most we expect UnsatisfiedLinkError.
-      jthrowable thrown = env->ExceptionOccurred();
-      env->ExceptionClear();
+    assert(env->ExceptionCheck());
 
-      jclass unsatisfied_link_error_clazz = env->FindClass("java/lang/UnsatisfiedLinkError");
-      jclass thrown_class = env->GetObjectClass(thrown);
-      assert(env->IsSameObject(unsatisfied_link_error_clazz, thrown_class));
-    }
+    // We expect UnsatisfiedLinkError.
+    jthrowable thrown = env->ExceptionOccurred();
+    env->ExceptionClear();
+
+    jclass unsatisfied_link_error_clazz = env->FindClass("java/lang/UnsatisfiedLinkError");
+    jclass thrown_class = env->GetObjectClass(thrown);
+    assert(env->IsSameObject(unsatisfied_link_error_clazz, thrown_class));
   }
 }