Without this change, parse failures result in an exception:
Traceback (most recent call last):
File "tst-glibcelf.py", line 23, in <module>
import glibcelf
File "/path/to/git/scripts/glibcelf.py", line 226, in <module>
_elf_h = _parse_elf_h()
File "/path/to/git/scripts/glibcelf.py", line 221, in _parse_elf_h
result = glibcpp.macro_eval(glibcpp.macro_definitions(tokens), reporter)
File "/path/to/git/scripts/glibcpp.py", line 379, in macro_eval
reporter.error(md.line, 'macro {} redefined'.format(md.name))
File "/path/to/git/scripts/glibcelf.py", line 214, in error
errors += 1
UnboundLocalError: local variable 'errors' referenced before assignment