There are many reasons why trying to handle malloc() returning NULL by
any other way than calling abort() is not beneficial:

- Usually malloc() does not return NULL, thanks to memory overcommit.
  Instead, the program gets SIGSEGV signal when it tries to access the
  memory.

- Trying to handle NULL will create failure paths that are impractical
  to test. There is no way to be sure the compositor still works once
  such path is actually taken.

- Those failure path will clutter the code, increasing maintenance and
  development burden.

- Sometimes there just isn't a good way to handle the failure.

For more discussion, see the issue link below.

Closes: #631



Signed-off-by: Pekka Paalanen <pekka.paalanen@collabora.com>