Fix null pointer reference in shared_ptr destructor.

usbforward seems to crash once per session because shared_ptr is calling
custom destructor even if it is not initialized.

Test: manual
BUG=65264034
Change-Id: I123ec37b02921d7a7e6db264b21c04c414eb10d1
1 file changed
tree: 86ba6f5381b4524b64a06aecbe876b8570dcc875
  1. common/
  2. external/
  3. guest/
  4. host/
  5. tools/
  6. BUILD
  7. WORKSPACE