configure: Use the correct help string macro.

configure.ac

@@ -72,7 +72,7 @@ AC_ARG_WITH(pcap,      AS_HELP_STRING([--without-pcap],[do not use the Packet Ca
 AC_ARG_WITH(png,       AS_HELP_STRING([--without-png],[do not use PNG]))
 AC_ARG_WITH(pthread,   AS_HELP_STRING([--without-pthread],[do not use the pthread library]),
             [if test "x$withval" = "xno"; then ac_cv_header_pthread_h=no; fi])
-AC_ARG_WITH(pulse,     AC_HELP_STRING([--without-pulse],[do not use PulseAudio sound support]))
+AC_ARG_WITH(pulse,     AS_HELP_STRING([--without-pulse],[do not use PulseAudio sound support]))
 AC_ARG_WITH(sane,      AS_HELP_STRING([--without-sane],[do not use SANE (scanner support)]))
 AC_ARG_WITH(tiff,      AS_HELP_STRING([--without-tiff],[do not use TIFF]))
 AC_ARG_WITH(v4l,       AS_HELP_STRING([--without-v4l],[do not use v4l1 (v4l support)]))