This relaxes a check recently added to ScopedFDCloseTraits::Free to catch
double closes, which can be detected by checking for failures of close()
with errno of EBADF.

Unfortunately, some Linux drivers can return errors from close() other
than EBADF, but this does not indicate a failure to actually close the
file descriptor. Since r401427, such errors will cause a crash (e.g.
when unplugging your keyboard on Chrome OS - see crbug.com/681865).

Relax the check to only check for EBADF since this is the only status
that indicates a serious programming error.

BUG=660960

Review-Url: https://codereview.chromium.org/2642483002
Cr-Commit-Position: refs/heads/master@{#446119}