6141 use kmem_zalloc instead of kmem_alloc + bzero/memset

@@ -291,12 +291,11 @@
                 }
                 usage = RCTLOP_GET_USAGE(rctl, curproc);
                 mutex_exit(&rset->rcs_lock);
                 mutex_exit(&curproc->p_lock);
 
-                nblk = kmem_alloc(sizeof (rctl_opaque_t), KM_SLEEP);
-                bzero(nblk, sizeof (rctl_opaque_t));
+                nblk = kmem_zalloc(sizeof (rctl_opaque_t), KM_SLEEP);
                 nblk->rcq_value = usage;
 
                 ret = copyout(nblk, new_rblk, sizeof (rctl_opaque_t));
                 kmem_free(nblk, sizeof (rctl_opaque_t));
                 kmem_free(krde, sizeof (rctl_dict_entry_t));