Fix format errors in brick/iscsi LOG messages

Fix format errors in brick/iscsi LOG messages

Currently in cinder.brick.iscsi.iscs:LioADM.create_iscsi_target
The Log message for the exception is:
  LOG.error("%s" % e),

This rightfully results in:
  *** UnicodeError: UnicodeError(u'Message objects
      do not support str() because they may contain
      non-ascii characters. Please use unicode() or
      translate() instead.',)

In some cases this causes the Volume service to stop and
doesn't help a ton with debug. While looking at this also
noticed a number of other similar cases where invalid LOG
messages were set up.  Following the i8n guidelines here:
http://docs.openstack.org/developer/oslo.i18n/guidelines.html

Went ahead and cleaned the bulk of the LOG messages in this
file up to adhere to the guidelines as well as fixing the
UnicodeError described in the bug.

Change-Id: I33adf99ca25a2d8f869de5bfa85b4ca8429be05e