LU-11445 obd: remove portals handle from OBD import

LU-11445 obd: remove portals handle from OBD import

OBD imports are never looked up using the portals handle (imp_handle)
they contain, so remove it. Also remove the unused functions
class_conn2obd() and class_conn2cliimp().

Signed-off-by: John L. Hammond <jhammond@whamcloud.com>
Change-Id: Ib05f91f6dabbd4249769560d443ba69819fc1157
Reviewed-on: https://review.whamcloud.com/33250
Tested-by: Jenkins
Tested-by: Maloo <hpdd-maloo@intel.com>
Reviewed-by: Mike Pershin <mpershin@whamcloud.com>
Reviewed-by: James Simmons <uja.ornl@yahoo.com>
Reviewed-by: Oleg Drokin <green@whamcloud.com>