Fix exception throwing to support no detail message.

(The empty string as a detail message is distinct from a NULL detail message,
and is treated differently by Throwable.printStackTrace.)

Change-Id: I8c65deac9f18c5782dcf6e72e4c37e6dd4174fe9
diff --git a/src/dalvik_system_VMRuntime.cc b/src/dalvik_system_VMRuntime.cc
index 1bc1e39..8d4aa8b 100644
--- a/src/dalvik_system_VMRuntime.cc
+++ b/src/dalvik_system_VMRuntime.cc
@@ -56,7 +56,7 @@
     return NULL;
   }
   if (length < 0) {
-    Thread::Current()->ThrowNewException("Ljava/lang/NegativeArraySizeException;", "%d", length);
+    Thread::Current()->ThrowNewExceptionF("Ljava/lang/NegativeArraySizeException;", "%d", length);
     return NULL;
   }