drm/msm: Update global fault counter when faulty process has already ended

The global fault counter is no longer used since commit 12578c07
("drm/msm/gpu: Skip retired submits in recover worker"). However, it's
still needed, as we need to handle cases where a GPU fault occurs after
the faulting process has already ended.

Hence, increment the global fault counter when the submitting process
had already ended. This way, the number of faults returned by
MSM_PARAM_FAULTS will stay consistent.

While here, s/unusuable/unusable.

Fixes: 12578c07 ("drm/msm/gpu: Skip retired submits in recover worker")
Signed-off-by: Maíra Canal <mcanal@igalia.com>
Patchwork: https://patchwork.freedesktop.org/patch/664853/


Signed-off-by: Rob Clark <robin.clark@oss.qualcomm.com>