cifs: Display strictcache mount option in /proc/mounts

Commit d39454ffe4a3c85428483b8a8a8e5e797b6363d5 adds a strictcache mount
option. This patch allows the display of this mount option in
/proc/mounts when listing shares mounted with the strictcache mount
option.

Signed-off-by: Sachin Prabhu <sprabhu@redhat.com>
Reviewed-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Steve French <smfrench@gmail.com>