drm/msm/adreno: Do not propagate void return values

With sparse ("make C=2"), lots of

  error: return expression in void function

messages are seen.

Fix this by removing the return statements to propagate void return
values.

Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
Reviewed-by: Guenter Roeck <linux@roeck-us.net>
Patchwork: https://patchwork.freedesktop.org/patch/492529/
Link: https://lore.kernel.org/r/0083bc7e23753c19902580b902582ae499b44dbf.1657113388.git.geert@linux-m68k.org


Signed-off-by: Rob Clark <robdclark@chromium.org>