Fix invalid usage of codearchiver.subprocess

Introduced by 240dcceb

codearchiver/modules/git.py

@@ -50,10 +50,10 @@ class Git(codearchiver.core.Module):
 		if self._extraBranches:
 			for branch, commit in self._extraBranches.items():
 				_logger.info(f'Fetching commit {commit} as {branch}')
-				r = codearchiver.subprocess.run_with_log(['git', 'fetch', '--verbose', '--progress', 'origin', commit], cwd = directory, check = False)
-				if r.returncode == 0:
-					r2 = codearchiver.subprocess.run_with_log(['git', 'update-ref', f'refs/codearchiver/{branch}', commit, ''], cwd = directory, check = False)
-					if r2.returncode != 0:
+				r, _ = codearchiver.subprocess.run_with_log(['git', 'fetch', '--verbose', '--progress', 'origin', commit], cwd = directory, check = False)
+				if r == 0:
+					r2, _ = codearchiver.subprocess.run_with_log(['git', 'update-ref', f'refs/codearchiver/{branch}', commit, ''], cwd = directory, check = False)
+					if r2 != 0:
 						_logger.error(f'Failed to update-ref refs/codearchiver/{branch} to {commit}')
 				else:
 					_logger.error(f'Failed to fetch {commit}')