nfsd4: simplify references to nfsd4 lease time

Instead of accessing the lease time directly, some users call
nfs4_lease_time(), and some a macro, NFSD_LEASE_TIME, defined as
nfs4_lease_time().  Neither layer of indirection serves any purpose.

Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
diff --git a/fs/nfsd/nfs4xdr.c b/fs/nfsd/nfs4xdr.c
index c458fb1..f61bd73 100644
--- a/fs/nfsd/nfs4xdr.c
+++ b/fs/nfsd/nfs4xdr.c
@@ -1899,7 +1899,7 @@
 	if (bmval0 & FATTR4_WORD0_LEASE_TIME) {
 		if ((buflen -= 4) < 0)
 			goto out_resource;
-		WRITE32(NFSD_LEASE_TIME);
+		WRITE32(nfsd4_lease);
 	}
 	if (bmval0 & FATTR4_WORD0_RDATTR_ERROR) {
 		if ((buflen -= 4) < 0)