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

@@ -756,11 +756,11 @@
         if (capability == S_CAPABILITY_NOMINFLT)
                 return (1);
         return (0);
 }
 
-static struct seg_ops segkmem_ops = {
+static const struct seg_ops segkmem_ops = {
         .fault          = segkmem_fault,
         .setprot        = segkmem_setprot,
         .checkprot      = segkmem_checkprot,
         .kluster        = segkmem_kluster,
         .dump           = segkmem_dump,