tests: more automated quote adjustment

Relax initial regexp to match more instances, but add a
filter to avoid some invalid conversions.  Run this:

git grep -l "\`[^']*'" tests | xargs perl -pi -e '$q=q"'\''";' \
  -e '$q="$q\\$q$q"; /(= ?\`|\`expr|\`echo|\Q$q\E)/ and next;' \
  -e ' s/\`([^'\''"]*?'\'')/'\''$1/g'
The last disjunct in the above (...) filter is to exempt
any line that contains this string: '\''
With quoting like that, converting a ` to ' is likely to cause trouble,
so we'll handle those manually.  Here are three examples where
the exemption is required:

  *': `link-to-dir/'\'': hard link not allowed for directory'*) ;;
  printf 'creating file `%s'\''\n' $f
  'mv: inter-device move failed: `%s'\'' to `%s'\'';'\

1 files changed, 1 insertions, 1 deletions

diff --git a/tests/rm/no-give-up b/tests/rm/no-give-up
index 690c5b617..2644c8afc 100755
--- a/tests/rm/no-give-up
+++ b/tests/rm/no-give-up
@@ -29,7 +29,7 @@ chown -R $NON_ROOT_USERNAME d || framework_failure_
 chmod go=x . || framework_failure_
 
 
-# This must fail, since `.' is not writable by $NON_ROOT_USERNAME.
+# This must fail, since '.' is not writable by $NON_ROOT_USERNAME.
 setuidgid $NON_ROOT_USERNAME env PATH="$PATH" rm -rf d 2>/dev/null && fail=1
 
 # d must remain.