global: convert indentation-TABs to spaces

Transformed via this shell code:
t=$'\t'
git ls-files \
  | grep -vE '(^|/)((GNU)?[Mm]akefile|ChangeLog)|\.(am|mk)$' \
  | grep -vE 'tests/pr/|help2man' \
  | xargs grep -lE "^ *$t" \
  | xargs perl -MText::Tabs -ni -le \
    '$m=/^( *\t[ \t]*)(.*)/; print $m ? expand($1) . $2 : $_'

tests/ls/stat-vs-dirent

@@ -45,9 +45,9 @@ while :; do
     # buggy file systems, at mount points.
     if test "$d_ino" != "$st_ino"; then
       echo "$0: test failed: $t/$file: d_ino($d_ino) != st_ino($st_ino)
-	This may indicate a flaw in your kernel or file system implementation.
-	The flaw isn't serious for coreutils, but it might break other tools,
-	so you should report it to your operating system vendor." 1>&2
+        This may indicate a flaw in your kernel or file system implementation.
+        The flaw isn't serious for coreutils, but it might break other tools,
+        so you should report it to your operating system vendor." 1>&2
 
       # This test fails too often, and we don't want to be distracted
       # with reports, since the code that could be affected by the losing