SUNRPC: Rename TCP receive-specific state variables

Since we will want to introduce similar TCP state variables for the
transmission of requests, let's rename the existing ones to label
that they are for the receive side.

Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>

include/linux/sunrpc/xprtsock.h

@@ -30,15 +30,17 @@ struct sock_xprt {
 	/*
 	 * State of TCP reply receive
 	 */
-	__be32			tcp_fraghdr,
-				tcp_xid,
-				tcp_calldir;
+	struct {
+		__be32		fraghdr,
+				xid,
+				calldir;
 
-	u32			tcp_offset,
-				tcp_reclen;
+		u32		offset,
+				len;
 
-	unsigned long		tcp_copied,
-				tcp_flags;
+		unsigned long	copied,
+				flags;
+	} recv;
 
 	/*
 	 * Connection of transports