NRG: Tidy up applyCommit (#5347)

This PR doesn't change any logical behaviour, it just removes
unnecessary `fpae` and `original` variables/steps.

Signed-off-by: Neil Twigg <neil@nats.io>

server/raft.go

@@ -2684,15 +2684,11 @@ func (n *raft) applyCommit(index uint64) error {
 		n.debug("Ignoring apply commit for %d, already processed", index)
 		return nil
 	}
-	original := n.commit
-	n.commit = index
 
 	if n.State() == Leader {
 		delete(n.acks, index)
 	}
 
-	var fpae bool
-
 	ae := n.pae[index]
 	if ae == nil {
 		var state StreamState
@@ -2710,15 +2706,14 @@ func (n *raft) applyCommit(index uint64) error {
 				// Reset and cancel any catchup.
 				n.resetWAL()
 				n.cancelCatchup()
-			} else {
-				n.commit = original
 			}
 			return errEntryLoadFailed
 		}
 	} else {
-		fpae = true
+		defer delete(n.pae, index)
 	}
 
+	n.commit = index
 	ae.buf = nil
 
 	var committed []*Entry
@@ -2793,9 +2788,6 @@ func (n *raft) applyCommit(index uint64) error {
 			committed = append(committed, e)
 		}
 	}
-	if fpae {
-		delete(n.pae, index)
-	}
 	// Pass to the upper layers if we have normal entries. It is
 	// entirely possible that 'committed' might be an empty slice here,
 	// which will happen if we've processed updates inline (like peer