smb3: display session id in debug data

Displaying the session id in /proc/fs/cifs/DebugData
is needed in order to correlate Linux client information
with network and server traces for many common support
scenarios.  Turned out to be very important for debugging.

Signed-off-by: Steve French <stfrench@microsoft.com>
CC: Stable <stable@vger.kernel.org>
Reviewed-by: Pavel Shilovsky <pshilov@microsoft.com>

fs/cifs/cifs_debug.c

@@ -380,6 +380,8 @@ static int cifs_debug_data_proc_show(struct seq_file *m, void *v)
 				atomic_read(&server->in_send),
 				atomic_read(&server->num_waiters));
 #endif
+			/* dump session id helpful for use with network trace */
+			seq_printf(m, " SessionId: 0x%llx", ses->Suid);
 			if (ses->session_flags & SMB2_SESSION_FLAG_ENCRYPT_DATA)
 				seq_puts(m, " encrypted");
 			if (ses->sign)