fix build issue with --enable-shared & --enable-vorbis

(should be reverted if ilbavformat ever gets really built as a shared lib)

Originally committed as revision 1680 to svn://svn.ffmpeg.org/ffmpeg/trunk

Makefile

@@ -41,10 +41,11 @@ DEP_LIBS=libavcodec/$(LIBPREF)avcodec$(LIBSUF) libavformat/$(LIBPREF)avformat$(L
 ifeq ($(CONFIG_MP3LAME),yes)
 EXTRALIBS+=-lmp3lame
 endif
+endif
+
 ifeq ($(CONFIG_VORBIS),yes)
 EXTRALIBS+=-logg -lvorbis -lvorbisenc
 endif
-endif
 
 ifeq ($(BUILD_VHOOK),yes)
 VHOOK=videohook