libav: fix checks for internal libav configure options

https://bugzilla.gnome.org/show_bug.cgi?id=691723

diff --git a/configure.ac b/configure.ac
index 28460f0..f830455 100644 (file)
--- a/configure.ac
+++ b/configure.ac
@@ -359,7 +359,7 @@ else
   fi
 
   dnl checks for extra enable/disable flags
-  LIBAV_OPTS="(cd $srcdir/gst-libs/ext/libav && ./configure --help)"
+  LIBAV_OPTS=`cd $srcdir/gst-libs/ext/libav && ./configure --help`
   # Let's check if we can disable the building of the libav binary
   can_disable=`echo "$LIBAV_OPTS" | grep 'disable-ffmpeg'`
   if test "$can_disable" != ""; then