drm/msm/adreno: remove return value of function XX_print

XX_print like pfp_print/me_print/meq_print/roq_print are just
used in file a5xx_debugfs.c. And these function always return
0, this return value is meaningless.
This change is to make the code a bit more readable.

Signed-off-by: Bernard Zhao <bernard@vivo.com>
Reviewed-by: Jordan Crouse <jcrouse@codeaurora.org>
Signed-off-by: Rob Clark <robdclark@chromium.org>