Fix --enable-assert-always-abort (but not --enable-debug) build

Look at NDEBUG, not OSL_DEBUG_LEVEL, to see whether asserts are active
or not.

Change-Id: I772d27da4bcc73c8c5a50ab4b72f50caddcf7273

bridges/source/cpp_uno/gcc3_macosx_x86-64/cpp2uno.cxx

@@ -109,7 +109,7 @@ static typelib_TypeClass cpp2uno_call(
 
         int nUsedGPR = 0;
         int nUsedSSE = 0;
-#if OSL_DEBUG_LEVEL > 0
+#ifndef NDEBUG
         bool bFitsRegisters =
 #endif
             x86_64::examine_argument( rParam.pTypeRef, false, nUsedGPR, nUsedSSE );