workaround the fact that VLC_ADD_LIBS appends arguments to the start of LIBS_plugin

configure.ac

@@ -1808,6 +1808,15 @@ if test "$SYS" = "linux" -a "${enable_linsys}" != "no"; then
   )
 fi
 
+dnl libdvdcss
+darwin_libdvdcss_extralibs="-Wl,-framework,CoreFoundation -Wl,-framework,IOKit"
+libdvdcss_extralibs=""
+test "${SYS}" = darwin && libdvdcss_extralibs="${darwin_libdvdcss_extralibs}"
+AC_CHECK_LIB(dvdcss, dvdcss_interface_2, [
+    VLC_ADD_LIBS([dvdread], -ldvdcss "${libdvdcss_extralibs}")
+    VLC_ADD_LIBS([dvdnav], -ldvdcss "${libdvdcss_extralibs}")
+    ],, "${libdvdcss_extralibs}")
+
 dnl
 dnl dvdread module: check for libdvdread
 dnl
@@ -1834,15 +1843,6 @@ then
       [AC_MSG_WARN([${DVDNAV_PKG_ERRORS}.])])
 fi
 
-dnl libdvdcss
-darwin_libdvdcss_extralibs="-Wl,-framework,CoreFoundation -Wl,-framework,IOKit"
-libdvdcss_extralibs=""
-test "${SYS}" = darwin && libdvdcss_extralibs="${darwin_libdvdcss_extralibs}"
-AC_CHECK_LIB(dvdcss, dvdcss_interface_2, [
-    VLC_ADD_LIBS([dvdread], -ldvdcss "${libdvdcss_extralibs}")
-    VLC_ADD_LIBS([dvdnav], -ldvdcss "${libdvdcss_extralibs}")
-    ],, "${libdvdcss_extralibs}")
-
 dnl
 dnl  Windows DirectShow access module
 dnl