[SCSI] iscsi bugfixes: fix oops when iser is flushing io

When we enter recovery and flush the running commands
we cannot freee the connection before flushing the commands.
Some commands may have a reference to the connection
that needs to be released before. iscsi_stop was forcing
the term and suspend too early and was causing a oops
in iser, so this patch removes those callbacks all together
and allows the LLD to handle that detail.

Signed-off-by: Mike Christie <michaelc@cs.wisc.edu>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>