cifs: convert list_for_each to entry variant

Convert list_for_each{,_safe} to list_for_each_entry{,_safe} in
cifs_mark_tcp_ses_conns_for_reconnect() function.

Signed-off-by: Paulo Alcantara (SUSE) <pc@cjr.nz>
Reviewed-by: Shyam Prasad N <sprasad@microsoft.com>
Signed-off-by: Steve French <stfrench@microsoft.com>