const-ify make segment ops structures
There is no reason to keep the segment ops structures writable.
patch lower-case-segops

*** 116,134 ****
   * Mappings of /dev/null come from segdev and have no mapping type.
   */
  
  #define SEG_IS_DEVNULL_MAPPING(seg)     \
          ((seg)->s_ops == &segdev_ops && \
!         ((SEGOP_GETTYPE(seg, (seg)->s_base) & (MAP_SHARED | MAP_PRIVATE)) == 0))
  
  extern void segdev_init(void);
  
  extern int segdev_create(struct seg *, void *);
  
  extern int segdev_copyto(struct seg *, caddr_t, const void *, void *, size_t);
  extern int segdev_copyfrom(struct seg *, caddr_t, const void *, void *, size_t);
! extern struct seg_ops segdev_ops;
  
  #endif  /* _KERNEL */
  
  #ifdef  __cplusplus
  }
--- 116,134 ----
   * Mappings of /dev/null come from segdev and have no mapping type.
   */
  
  #define SEG_IS_DEVNULL_MAPPING(seg)     \
          ((seg)->s_ops == &segdev_ops && \
!         ((segop_gettype((seg), (seg)->s_base) & (MAP_SHARED | MAP_PRIVATE)) == 0))
  
  extern void segdev_init(void);
  
  extern int segdev_create(struct seg *, void *);
  
  extern int segdev_copyto(struct seg *, caddr_t, const void *, void *, size_t);
  extern int segdev_copyfrom(struct seg *, caddr_t, const void *, void *, size_t);
! extern const struct seg_ops segdev_ops;
  
  #endif  /* _KERNEL */
  
  #ifdef  __cplusplus
  }