5045 use atomic_{inc,dec}_* instead of atomic_add_*

@@ -2572,11 +2572,11 @@
                 phdr_ah->ah_length = (ah_align_sz >> 2) + 1;
                 phdr_ah->ah_reserved = 0;
                 phdr_ah->ah_spi = assoc->ipsa_spi;
 
                 phdr_ah->ah_replay =
-                    htonl(atomic_add_32_nv(&assoc->ipsa_replay, 1));
+                    htonl(atomic_inc_32_nv(&assoc->ipsa_replay));
                 if (phdr_ah->ah_replay == 0 && assoc->ipsa_replay_wsize != 0) {
                         /*
                          * XXX We have replay counter wrapping.  We probably
                          * want to nuke this SA (and its peer).
                          */