drm/msm/a6xx: Fix a typo in an error message

'in' is duplicated in the error message. Axe one of them.
While at it, slighly improve indentation.

Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
Signed-off-by: Rob Clark <robdclark@chromium.org>