make: unifdef SUN5_0 (defined)

*** 51,63 ****
          struct { int mode;} mkdir;
          struct { char *name; int mode;} mount;
          struct { int flags; int mode;} open;
          struct { char *buffer; int buffer_size;} readlink;
          struct { struct stat *buffer;} stat;
- #ifndef SUN5_0
-         struct { struct statfs *buffer;} statfs;
- #endif
          struct { int length;} truncate;
          struct { struct timeval *time;} utimes;
  };
  
  extern  union Args      vroot_args;
--- 51,60 ----