Look for asoundlib.h in alsa, not sys.

git-svn-id: http://svn.xiph.org/trunk/ao@2430 0101bb08-14d6-0310-b084-bc0e0c8e3800

configure.in

@@ -185,7 +185,7 @@ AC_ARG_ENABLE(alsa09, [  --enable-alsa09           include alsa 0.9 output plugi
 
 if test "$BUILD_ALSA09" = "yes"; then
    AC_CHECK_LIB(asound, snd_pcm_open, have_alsa09=yes, have_alsa09=no)
-   AC_CHECK_HEADER(sys/asoundlib.h, , have_alsa09=no)
+   AC_CHECK_HEADER(alsa/asoundlib.h, , have_alsa09=no)
    AM_CONDITIONAL(HAVE_ALSA09,test "x$have_alsa09" = xyes)
 fi