SUNRPC: minor cleanup

RPC_DEBUG_DATA no longer needed in net/sunrpc/xprt.c.

Test plan:
Compile kernel with CONFIG_NFS enabled.

Signed-off-by: Chuck Lever <cel@netapp.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>

net/sunrpc/xprt.c

@@ -51,7 +51,6 @@
  */
 
 #ifdef RPC_DEBUG
-# undef  RPC_DEBUG_DATA
 # define RPCDBG_FACILITY	RPCDBG_XPRT
 #endif