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

@@ -1883,11 +1883,11 @@
         i = 2;
         for (seg = AS_SEGFIRST(as); seg != NULL; seg = AS_SEGNEXT(as, seg)) {
                 caddr_t eaddr = seg->s_base + pr_getsegsize(seg, 0);
                 caddr_t saddr, naddr;
                 void *tmp = NULL;
-                extern struct seg_ops segspt_shmops;
+                extern const struct seg_ops segspt_shmops;
 
                 for (saddr = seg->s_base; saddr < eaddr; saddr = naddr) {
                         uint_t prot;
                         size_t size;
                         int type;