[-Wformat] Fix scripty.cc again.

Seems like timeval is defined differently on OS X than on Linux. So
fixing the format specifier on one breaks it on the other. Explicitly
cast the value being passed in to fix the problem on both the platforms.

test/scripty.cc

@@ -623,7 +623,7 @@ int main(int argc, char *argv[])
 				fprintf(scripty_data.sd_to_child,
 					"sleep %ld.%06ld\n"
 					"write ",
-					diff.tv_sec, diff.tv_usec);
+					(long)diff.tv_sec, (long)diff.tv_usec);
 				dump_memory(scripty_data.sd_to_child,
 					    buffer,
 					    rc);