LU-1448 llite: Prevent NULL pointer dereference on disabled OSC

LU-1448 llite: Prevent NULL pointer dereference on disabled OSC

When a file system is mounted with a disabled OSC reading the import
information from the proc file system can result in a NULL pointer
dereference. The Lustre import on a disabled OSC with remain
in the LUSTRE_IMP_NEW state and imp_connection will remain NULL.

Signed-off-by: Jeremy Filizetti <jeremy.filizetti@gmail.com>
Signed-off-by: Bobi Jam <bobijam@whamcloud.com>
Change-Id: Ia6df51a36efbcd5a7fc7668bb23455b253ae4855
Reviewed-on: http://review.whamcloud.com/2995
Reviewed-by: Liang Zhen <liang@whamcloud.com>
Tested-by: Hudson
Tested-by: Maloo <whamcloud.maloo@gmail.com>
Reviewed-by: Oleg Drokin <green@whamcloud.com>