Minor fix for previous maintaining.texi change

* doc/emacs/maintaining.texi (VC Directory Commands): Use @file
for files.
1 job for master in 90 minutes and 1 second (queued for 4 seconds)
Status Job ID Name Coverage
  Test
failed #3310
test-all

01:30:01

 
Name Stage Failure
failed
test-all Test The script exceeded the maximum execution time set for the job
  ELC      textmodes/refill.elc
ELC textmodes/reftex-auc.elc
ELC textmodes/reftex-cite.elc
ELC textmodes/reftex-dcr.elc
ELC textmodes/reftex-global.elc
ELC textmodes/reftex-index.elc
ELC textmodes/reftex-parse.elc
Pulling docker image gitlab/gitlab-runner-helper:x86_64-d0b76032 ...
ERROR: Job failed: execution took longer than 1h30m0s seconds