[alsa-utils][PATCH 2/5] configure.ac: fix the check for xmlto availability

[Antonio Ospite <ao2@ao2.it>]

The same $xmlto variable is used both in AC_ARG_ENABLE and
AC_CHECK_PROG, but the latter is not setting a value to it when the
program is not found.

These two facts result in the "yes" value from the AC_ARG_ENABLE macro
to be still kept in the variable when the program is not found by
AC_CHECK_PROG, causing USE_XMLTO to be always set, finally resulting in
a build failure in case the xmlto program is not actually in the PATH.

As possible fix could have been to set "no" as a value in AC_CHECK_PROG
when program is not found.

However using two separate variables is more explicit, so fix the issue
this way.

Signed-off-by: Antonio Ospite <ao2@ao2.it>
---
 configure.ac | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/configure.ac b/configure.ac
index 2221617..c9629bb 100644
--- a/configure.ac
+++ b/configure.ac
@@ -166,14 +166,14 @@ AC_ARG_ENABLE(alsaloop,
      esac],[alsaloop=true])
 AM_CONDITIONAL(ALSALOOP, test x$alsaloop = xtrue)
 
-xmlto=""
+xmlto_available=""
 AC_ARG_ENABLE(xmlto,
  AS_HELP_STRING([--disable-xmlto], [Disable man page creation via xmlto]),
  xmlto="$enableval", xmlto="yes")
 if test "$xmlto" = "yes"; then
-  AC_CHECK_PROG([xmlto], [xmlto], [yes])
+  AC_CHECK_PROG([xmlto_available], [xmlto], [yes])
 fi
-AM_CONDITIONAL(USE_XMLTO, test x"$xmlto" = xyes)
+AM_CONDITIONAL(USE_XMLTO, test x"$xmlto_available" = xyes)
 
 AC_ARG_WITH(
         [udev-rules-dir],
-- 
2.11.0