Allow connect by FC-only or iSCSI-only systems.

Currently the brick code raises exceptions if it cannot determine the
initiator name or FC HBA information. This patch makes this information
optional, as Nova does.

Fixes: bug 1203486

Change-Id: I8efc101d7ac980261a8bc5d74209cafe4b06cc15
Merge "Allow connect by FC-only or iSCSI-only systems."