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

@@ -1542,13 +1542,13 @@
                  * get it).
                  */
                 if (throttle_write) {
                         if (sema_tryp(&cmap->cmap_throttle_sem) == 0) {
                                 rw_exit(&sidp->sid_rwlock);
-                                atomic_add_32(&cmap->cmap_waiters, 1);
+                                atomic_inc_32(&cmap->cmap_waiters);
                                 sema_p(&cmap->cmap_throttle_sem);
-                                atomic_add_32(&cmap->cmap_waiters, -1);
+                                atomic_dec_32(&cmap->cmap_waiters);
                                 rw_enter(&sidp->sid_rwlock, RW_READER);
 
                         /*
                          * Now since we released the sid_rwlock the state may
                          * have transitioned underneath us. so check that again.

@@ -1678,11 +1678,11 @@
                         sema_v(&cmap->cmap_throttle_sem);
                 return;
         }
         rw_exit(&sidp->sid_rwlock);
 
-        atomic_add_64((uint64_t *)&cmap->cmap_nchunks, 1);
+        atomic_inc_64((uint64_t *)&cmap->cmap_nchunks);
 
         if ((cmap->cmap_maxsize != 0) &&
             ((cmap->cmap_nchunks * cmap->cmap_chunksz) > cmap->cmap_maxsize)) {
                 cmn_err(CE_WARN, "fssnap_write_taskq: snapshot %d (%s) has "
                     "reached the maximum backing file size specified (%llu "