setuid doesn't correctly set the umask

In the native code for the new (in 6.1) "setuid" feature, an invalid value is being passed to the umask function.

In the file extras/setuid/src/main/native/org_mortbay_setuid_SetUID.c, a pointer to the umask function is cast to an integer and passed to the umask function. This is incorrect...the function argument should be passed to umask.

The attached patch fixes the problem.