NFS: use documenting macro constants for initializing ac{reg, dir}{min, max}

Clean up.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
diff --git a/fs/nfs/nfsroot.c b/fs/nfs/nfsroot.c
index 15afe3a..46763d1c 100644
--- a/fs/nfs/nfsroot.c
+++ b/fs/nfs/nfsroot.c
@@ -295,10 +295,10 @@
 	nfs_data.flags    = NFS_MOUNT_NONLM;	/* No lockd in nfs root yet */
 	nfs_data.rsize    = NFS_DEF_FILE_IO_SIZE;
 	nfs_data.wsize    = NFS_DEF_FILE_IO_SIZE;
-	nfs_data.acregmin = 3;
-	nfs_data.acregmax = 60;
-	nfs_data.acdirmin = 30;
-	nfs_data.acdirmax = 60;
+	nfs_data.acregmin = NFS_DEF_ACREGMIN;
+	nfs_data.acregmax = NFS_DEF_ACREGMAX;
+	nfs_data.acdirmin = NFS_DEF_ACDIRMIN;
+	nfs_data.acdirmax = NFS_DEF_ACDIRMAX;
 	strcpy(buf, NFS_ROOT);
 
 	/* Process options received from the remote server */