selftests: net: tcp_mmap: fix SO_RCVLOWAT setting

Since chunk_size is no longer an integer, we can not
use it directly as an argument of setsockopt().

This patch should fix tcp_mmap for Big Endian kernels.

Fixes: 597b01ed ("selftests: net: avoid ptl lock contention in tcp_mmap")
Signed-off-by: NEric Dumazet <edumazet@google.com>
Cc: Soheil Hassas Yeganeh <soheil@google.com>
Cc: Arjun Roy <arjunroy@google.com>
Acked-by: NSoheil Hassas Yeganeh <soheil@google.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

tools/testing/selftests/net/tcp_mmap.c

@@ -282,12 +282,14 @@ static void setup_sockaddr(int domain, const char *str_addr,
 static void do_accept(int fdlisten)
 {
 	pthread_attr_t attr;
+	int rcvlowat;
 
 	pthread_attr_init(&attr);
 	pthread_attr_setdetachstate(&attr, PTHREAD_CREATE_DETACHED);
 
+	rcvlowat = chunk_size;
 	if (setsockopt(fdlisten, SOL_SOCKET, SO_RCVLOWAT,
-		       &chunk_size, sizeof(chunk_size)) == -1) {
+		       &rcvlowat, sizeof(rcvlowat)) == -1) {
 		perror("setsockopt SO_RCVLOWAT");
 	}