coresight: fix error checks for byte counter init code

Fix error checks for byte counter initialization functions that
are called during probe to avoid null pointer accesses.

CRs-Fixed: 562303
Change-Id: I8f7de6fc4b0658cf649e472d12a00ea5733a8b0a
Signed-off-by: Pratik Patel <pratikp@codeaurora.org>