wrapper.c: consistently quote filenames in error messages
All other error messages in the file use quotes around the file name.
This change removes two translations as "could not write to '%s'" and
"could not close '%s'" are already translated and these two are the only
occurrences without quotes.
Signed-off-by: Simon Ruderich <simon@ruderich.org>
[jc: adjusted tests I noticed were broken by the change] Signed-off-by: Junio C Hamano <gitster@pobox.com>