msm: kgsl: Limit the HFI error log to 16 characters

The HFI error message has a 16 character error string attached. We should
not trust that the error string is properly formatted with a null
character at the end. Set the string precision to ensure that we only
print up to 16 characters of the payload.

Change-Id: Ic0dedbad1b2aebef1feb3f9f7f531869e96599e6
Signed-off-by: Jordan Crouse <jcrouse@codeaurora.org>