nfscl: Do not delay recovery for a stale ClientID

When a CREATE_SESSION with the extant ClientID failed with
NFS4ERR_STALE_CLIENTID within nfsc_renew of the previous full recovery,
nfsrpc_setclient() returned EIO and the mount did no I/O until that window
expired (about 45s).
The server has discarded the ClientID, so waiting cannot help; RFC 8881
Section 8.4.2 requires a new ClientID (EXCHANGE_ID) and a state reclaim.

AWS EFS discards both the session and the ClientID of clients whose lease is
current whenever it resets a connection, which makes this path common there.

PR:		299221
Approved by:	rmacklem@
Sponsored by:	Netflix

sys/fs/nfsclient/nfs_clrpcops.c

@@ -1069,12 +1069,15 @@ nfsrpc_setclient(struct nfsmount *nmp, struct nfsclclient *clp, int reclaim,
 				nfscl_freenfsclds(dsp);
 				dsp = NULL;
 				/*
-				 * If *retokp is true, return any error other
-				 * than NFSERR_STALECLIENTID,
+				 * A stale ClientID needs a full recovery.
+				 * Otherwise, if *retokp is true, return any
+				 * error other than NFSERR_STALECLIENTID,
 				 * NFSERR_BADSESSION or NFSERR_STALEDONTRECOVER
 				 * so that nfscl_recover() will not loop.
 				 */
-				if (*retokp)
+				if (error == NFSERR_STALECLIENTID)
+					*retokp = false;
+				else if (*retokp)
 					return (NFSERR_IO);
 			} else
 				*retokp = true;