SUNRPC: Use kmemdup_nul() in rpc_parse_scope_id()

Using kmemdup_nul() is more efficient when the length is known.
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>

net/sunrpc/addr.c

@@ -175,7 +175,7 @@ static int rpc_parse_scope_id(struct net *net, const char *buf,
 		return 0;
 
 	len = (buf + buflen) - delim - 1;
-	p = kstrndup(delim + 1, len, GFP_KERNEL);
+	p = kmemdup_nul(delim + 1, len, GFP_KERNEL);
 	if (p) {
 		u32 scope_id = 0;
 		struct net_device *dev;