People do not read the README and seem to like to
unselect the crc32c module even though iscsi_tcp selects
it for them. This patch spits a error that tells the user
that they really do need the module. Hopefully, we will
get fewer people asking about this now.
Signed-off-by: Mike Christie <michaelc@cs.wisc.edu>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>