SUNRPC: remove duplicated include from clnt.c

Remove duplicated include.

Signed-off-by: Wei Yongjun <yongjun_wei@trendmicro.com.cn>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>

net/sunrpc/clnt.c

@@ -31,7 +31,6 @@
 #include <linux/in.h>
 #include <linux/in6.h>
 #include <linux/un.h>
-#include <linux/rcupdate.h>
 
 #include <linux/sunrpc/clnt.h>
 #include <linux/sunrpc/addr.h>