cifs: move SMB FSCTL definitions to common code

The FSCTL definitions are in smbfsctl.h which should be
shared by client and server.  Move the updated version of
smbfsctl.h into smbfs_common and have the client code use
it (subsequent patch will change the server to use this
common version of the header).

Reviewed-by: Ronnie Sahlberg <lsahlber@redhat.com>
Signed-off-by: Steve French <stfrench@microsoft.com>