cifs: handle cases where multiple sessions share connection

cifs: handle cases where multiple sessions share connection

[ Upstream commit a39c757bf0596b17482a507f31c3ef0af0d1d2b4 ]

Based on our implementation of multichannel, it is entirely
possible that a server struct may not be found in any channel
of an SMB session.

In such cases, we should be prepared to move on and search for
the server struct in the next session.

Signed-off-by: Shyam Prasad N <sprasad@microsoft.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>