Remove include userdefs.h where not needed

*** 32,42 ****
   */
  
  #include <errno.h>
  #include <sys/types.h>
  #include <stdio.h>
- #include <userdefs.h>
  #include <pwd.h>
  #include <libcmdutils.h>
  
  static int findunuseduid(uid_t start, uid_t stop, uid_t *ret);
  static boolean_t isreserveduid(uid_t uid);
--- 32,41 ----