Remove include userdefs.h where not needed

*** 31,41 ****
   */
  
  #include <errno.h>
  #include <sys/types.h>
  #include <stdio.h>
- #include <userdefs.h>
  #include <grp.h>
  #include <libcmdutils.h>
  
  static int findunusedgid(gid_t start, gid_t stop, gid_t *ret);
  static boolean_t isreservedgid(gid_t gid);
--- 31,40 ----