Silence GCC-4.5.3 warning about unused result in d8.cc

TEST=GCC 4.5.3 successfully compiles d8.cc even with -Werror enabled.

Review URL: http://codereview.chromium.org/8296018

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@9679 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

src/d8.cc

@@ -178,7 +178,8 @@ bool Shell::ExecuteString(Handle<String> source,
         // If all went well and the result wasn't undefined then print
         // the returned value.
         v8::String::Utf8Value str(result);
-        fwrite(*str, sizeof(**str), str.length(), stdout);
+        size_t count = fwrite(*str, sizeof(**str), str.length(), stdout);
+        (void) count;  // Silence GCC-4.5.x "unused result" warning.
         printf("\n");
       }
       return true;