gralloc: fix nullptr dereference

This happens only for host side tests where we free and unregister
in the same process. Post-Treble Android usually expects not to do this.

However, this CL should not affect behavior of guests either pre or post
Treble.

Change-Id: I4fac91c6d4c7031ac19e7c75233451663e3d31c4
1 file changed
tree: 47ec3718eee9749c4a55736938de872cf0d2a904
  1. host/
  2. shared/
  3. system/
  4. tests/
  5. Android.mk
  6. common.mk
  7. README