kvs: add root_seq to kvstxn_process()

Problem: In the near future we will need to root sequence
number in kvstxn_process(), but it is not available.

Solution: Add root_seq parameter to kvstxn_process().  Update
callers appropriately.

src/modules/kvs/kvs.c

@@ -963,7 +963,9 @@ static void kvstxn_apply (kvstxn_t *kt)
     if ((errnum = kvstxn_get_aux_errnum (kt)))
         goto done;
 
-    if ((ret = kvstxn_process (kt, root->ref)) == KVSTXN_PROCESS_ERROR) {
+    if ((ret = kvstxn_process (kt,
+                               root->ref,
+                               root->seq)) == KVSTXN_PROCESS_ERROR) {
         errnum = kvstxn_get_errnum (kt);
         goto done;
     }

src/modules/kvs/kvstxn.c

@@ -842,7 +842,9 @@ static json_t *keys_from_ops (json_t *ops)
     return NULL;
 }
 
-kvstxn_process_t kvstxn_process (kvstxn_t *kt, const char *root_ref)
+kvstxn_process_t kvstxn_process (kvstxn_t *kt,
+                                 const char *root_ref,
+                                 int root_seq)
 {
     /* Incase user calls kvstxn_process() again */
     if (kt->errnum)

src/modules/kvs/kvstxn.h

@@ -113,7 +113,9 @@ json_t *kvstxn_get_keys (kvstxn_t *kt);
  * on completion, call kvstxn_get_newroot_ref() to get reference to
  * new root to be stored.
  */
-kvstxn_process_t kvstxn_process (kvstxn_t *kt, const char *root_ref);
+kvstxn_process_t kvstxn_process (kvstxn_t *kt,
+                                 const char *root_ref,
+                                 int root_seq);
 
 /* on stall, iterate through all missing refs that the caller should
  * load into the cache