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

@@ -133,11 +133,11 @@
 static int      segvn_getmemid(struct seg *seg, caddr_t addr,
                     memid_t *memidp);
 static lgrp_mem_policy_info_t   *segvn_getpolicy(struct seg *, caddr_t);
 static int      segvn_inherit(struct seg *, caddr_t, size_t, uint_t);
 
-struct  seg_ops segvn_ops = {
+const struct seg_ops segvn_ops = {
         .dup            = segvn_dup,
         .unmap          = segvn_unmap,
         .free           = segvn_free,
         .fault          = segvn_fault,
         .faulta         = segvn_faulta,