drm/msm/dsi-staging: improve ESD error logging

Sometimes during ESD check in driver, the display panel
might return some wrong value which is not captured as
part of failure log. This change improves the same by
printing the panel return value, which will tell what was
the status of panel when issue happened.

Change-Id: I10618dc41b067932ae27a5c60c85565fb136f0ea
Signed-off-by: Sandeep Panda <spanda@codeaurora.org>