remove manually freeing the variable mDeathRecipient

The variable `mDeathRecipient` will automatically free the allocated
memory when it is destructed. This CL deletes the code for manually
releasing the variable `mDeathRecipient` to avoid the same variable
being freed twice.

Bug: 296617022
Test: Run fuzzer test.
Change-Id: I733f7f8d26e48a9434d41c5098f39ad91208abeb
2 files changed