The Linux Coding Style enumerates a few special cases where typedefs
are useful, but stresses "NEVER EVER use a typedef unless you can
clearly match one of those rules." The hdd_context_t typedef does not
meet any of those criteria, so replace references to it with a
reference to the underlying struct.
Change-Id: I5ac8829606eda6940deebe13037e15e47bed6f9b
CRs-Fixed: 2100188