drm/msm: remove msm_gem_free_work

Now that we don't need struct_mutex in the free path, we can get rid of
the asynchronous free all together.

Change-Id: I82406450e3a5d0d49d3fb753c621f55e8f4af088
Signed-off-by: Rob Clark <robdclark@chromium.org>
Git-commit: c951a9b284b907604759628d273901064c60d09f
Git-repo: git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
Signed-off-by: Samantha Tran <samtran@codeaurora.org>

msm/msm_gem.h

@@ -184,7 +184,6 @@ enum msm_gem_lock {
 
 void msm_gem_purge(struct drm_gem_object *obj, enum msm_gem_lock subclass);
 void msm_gem_vunmap(struct drm_gem_object *obj, enum msm_gem_lock subclass);
-void msm_gem_free_work(struct work_struct *work);
 
 /* Created per submit-ioctl, to track bo's and cmdstream bufs, etc,
  * associated with the cmdstream submission for synchronization (and