NFS: Use proper naming conventions for nfs_client.impl_id field

Clean up:  When naming fields and data types, follow established
conventions to facilitate accurate grep/cscope searches.

Additionally, for consistency, move the impl_id field into the NFSv4-
specific part of the nfs_client, and free that memory in the logic
that shuts down NFSv4 nfs_clients.

Introduced by commit 7d2ed9ac "NFSv4: parse and display server
implementation ids," Fri Feb 17, 2012.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
diff --git a/fs/nfs/nfs4proc.c b/fs/nfs/nfs4proc.c
index 94494f2..daa4e1b 100644
--- a/fs/nfs/nfs4proc.c
+++ b/fs/nfs/nfs4proc.c
@@ -5119,8 +5119,8 @@
 
 	if (!status) {
 		/* use the most recent implementation id */
-		kfree(clp->impl_id);
-		clp->impl_id = res.impl_id;
+		kfree(clp->cl_implid);
+		clp->cl_implid = res.impl_id;
 	} else
 		kfree(res.impl_id);
 
@@ -5144,12 +5144,12 @@
 out_server_scope:
 	kfree(res.server_scope);
 out:
-	if (clp->impl_id)
+	if (clp->cl_implid)
 		dprintk("%s: Server Implementation ID: "
 			"domain: %s, name: %s, date: %llu,%u\n",
-			__func__, clp->impl_id->domain, clp->impl_id->name,
-			clp->impl_id->date.seconds,
-			clp->impl_id->date.nseconds);
+			__func__, clp->cl_implid->domain, clp->cl_implid->name,
+			clp->cl_implid->date.seconds,
+			clp->cl_implid->date.nseconds);
 	dprintk("<-- %s status= %d\n", __func__, status);
 	return status;
 }