Consistently use $(BUILD_ROOT).

Originally committed as revision 6695 to svn://svn.ffmpeg.org/ffmpeg/trunk

configure

@@ -605,7 +605,7 @@ v4l="no"
 v4l2="no"
 audio_oss="yes"
 dv1394="no"
-VHOOKSHFLAGS="-shared -L../libavformat -L../libavcodec -L../libavutil"
+VHOOKSHFLAGS='-shared -L$(BUILD_ROOT)/libavformat -L$(BUILD_ROOT)/libavcodec -L$(BUILD_ROOT)/libavutil'
 VHOOKLIBS='-lavformat$(BUILDSUF) -lavcodec$(BUILDSUF) -lavutil$(BUILDSUF) $(EXTRALIBS)'
 extralibs=""
 EXESUF=".exe"

libavformat/Makefile

@@ -161,7 +161,7 @@ OBJS-$(CONFIG_AUDIO_DEMUXER)             += audio.o
 OBJS-$(CONFIG_AUDIO_MUXER)               += audio.o
 endif
 
-EXTRALIBS := -lavcodec$(BUILDSUF) -L../libavcodec $(EXTRALIBS)
+EXTRALIBS := -lavcodec$(BUILDSUF) -L$(BUILD_ROOT)/libavcodec $(EXTRALIBS)
 
 ifeq ($(CONFIG_AUDIO_BEOS),yes)
 CPPOBJS+= beosaudio.o