net: ipv4: tcp: Get tcpi_count via file_count() not direct access

Commit 0a1544a, which implements a Qualcomm feature called
Smart Wireless Interface Manager, added a tcpi_count member to
struct tcp_info, and populates it using:

    atomic_read(&filep->f_count);

This causes compiler warnings on 64-bit architectures (e.g.,
64-bit ARCH_UM, used by net_test) because f_count is actually an
atomic_long_t, and on 64-bit architectures atomic_long_t is a
64-bit number. The difference doesn't matter in practice because
the value is cast to a __u8 anyway, but it causes build breaks
because we build with -Werror.

Instead of using atomic_long_t directly, use the the file_count
macro which exists for this purpose.

Change-Id: Ie09a0b4e7a5cf128b21eff10c1b34faf5c995356
Signed-off-by: Lorenzo Colitti <lorenzo@google.com>

Author: lcolitti

net/ipv4/tcp.c

@@ -2523,7 +2523,7 @@ void tcp_get_info(const struct sock *sk, struct tcp_info *info)
 	if (sk->sk_socket) {
 		struct file *filep = sk->sk_socket->file;
 		if (filep)
-			info->tcpi_count = atomic_read(&filep->f_count);
+			info->tcpi_count = file_count(filep);
 	}
 }
 EXPORT_SYMBOL_GPL(tcp_get_info);