8169201: Montgomery multiply intrinsic should use correct name

Summary: Corrected stubName to montgomery_multiply for inline_montgomeryMultiply()
Reviewed-by: aph, thartmann, zmajo

src/share/vm/opto/library_call.cpp

@@ -6026,7 +6026,7 @@ bool LibraryCallKit::inline_montgomeryMultiply() {
   }
 
   assert(UseMontgomeryMultiplyIntrinsic, "not implemented on this platform");
-  const char* stubName = "montgomery_square";
+  const char* stubName = "montgomery_multiply";
 
   assert(callee()->signature()->size() == 7, "montgomeryMultiply has 7 parameters");