nfsd4: Use kmemdup rather than duplicating its implementation

The semantic patch that makes this change is available
in scripts/coccinelle/api/memdup.cocci.

Signed-off-by: Thomas Meyer <thomas@m3y3r.de>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
diff --git a/fs/nfsd/nfs4state.c b/fs/nfsd/nfs4state.c
index a84978c..6ab6779 100644
--- a/fs/nfsd/nfs4state.c
+++ b/fs/nfsd/nfs4state.c
@@ -986,12 +986,11 @@
 	clp = kzalloc(sizeof(struct nfs4_client), GFP_KERNEL);
 	if (clp == NULL)
 		return NULL;
-	clp->cl_name.data = kmalloc(name.len, GFP_KERNEL);
+	clp->cl_name.data = kmemdup(name.data, name.len, GFP_KERNEL);
 	if (clp->cl_name.data == NULL) {
 		kfree(clp);
 		return NULL;
 	}
-	memcpy(clp->cl_name.data, name.data, name.len);
 	clp->cl_name.len = name.len;
 	return clp;
 }