scsi: ufs-debugfs: Fix hba access

Don't access hba when its NULL.

CRs-Fixed: 1001231
Change-Id: I0a4f0606a7c582de436071f33e0b9e49c771c63d
Signed-off-by: Venkat Gopalakrishnan <venkatg@codeaurora.org>
[cang@codeaurora.org: resolved trivial merge conflicts]
Signed-off-by: Can Guo <cang@codeaurora.org>