configure*: Add missing quotes to arguments

For increased safety and consistency.  In addition, this should make it
clearer where each argument starts and ends.

See also the following item from autoconf NEWS[1]:

> * Noteworthy changes in release 2.70 (2020-12-08) [stable]

[...]

> *** Many macros have become pickier about argument quotation.
>
>   If you get a shell syntax error from your generated configure
>   script, or seemingly impossible misbehavior (e.g. entire blocks of
>   the configure script not getting executed), check first that all
>   macro arguments are properly quoted. The “M4 Quotation” section of
>   the manual explains how to quote macro arguments properly.
>
>   It is unfortunately not possible for autoupdate to correct
>   quotation errors.

[1] https://git.savannah.gnu.org/gitweb/?p=autoconf.git;a=blob;f=NEWS;h=ba418d1af5da752de77a2c388f9af56f8f1bf6a4;hb=97fbc5c184acc6fa591ad094eae86917f03459fa

1 files changed, 2 insertions, 2 deletions

diff --git a/configure b/configure
index ba553102d..0aa278e94 100755
--- a/configure
+++ b/configure
@@ -3562,10 +3562,10 @@ HAVE_OVERLAYFS=""
 
 #
 #AC_ARG_ENABLE([overlayfs],
-#    AS_HELP_STRING([--disable-overlayfs], [disable overlayfs]))
+#    [AS_HELP_STRING([--disable-overlayfs], [disable overlayfs])])
 #AS_IF([test "x$enable_overlayfs" != "xno"], [
 #       HAVE_OVERLAYFS="-DHAVE_OVERLAYFS"
-#       AC_SUBST(HAVE_OVERLAYFS)
+#       AC_SUBST([HAVE_OVERLAYFS])
 #])
 
 HAVE_OUTPUT=""