SUNRPC: Fix an unnecessary implicit type cast in rpcrdma_count_chunks()

Nit: rl_nchunks is an unsigned integer, so pass it into
rpcrdma_count_chunks() via an unsigned integer argument.  This eliminates
a harmless mixed sign comparison in rpcrdma_count_chunks()
Signed-off-by: NChuck Lever <chuck.lever@oracle.com>
Cc: Thomas Talpey <Thomas.Talpey@netapp.com>
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

net/sunrpc/xprtrdma/rpc_rdma.c

@@ -552,7 +552,7 @@ rpcrdma_marshal_req(struct rpc_rqst *rqst)
  * RDMA'd by server. See map at rpcrdma_create_chunks()! :-)
  */
 static int
-rpcrdma_count_chunks(struct rpcrdma_rep *rep, int max, int wrchunk, __be32 **iptrp)
+rpcrdma_count_chunks(struct rpcrdma_rep *rep, unsigned int max, int wrchunk, __be32 **iptrp)
 {
 	unsigned int i, total_len;
 	struct rpcrdma_write_chunk *cur_wchunk;