lavf/Makefile: fix standalone compilation of live_flv demuxer

Signed-off-by: James Almer <jamrial@gmail.com>
Signed-off-by: Michael Niedermayer <michaelni@gmx.at>

libavformat/Makefile

@@ -146,6 +146,7 @@ OBJS-$(CONFIG_FLAC_MUXER)                += flacenc.o flacenc_header.o \
                                             vorbiscomment.o
 OBJS-$(CONFIG_FLIC_DEMUXER)              += flic.o
 OBJS-$(CONFIG_FLV_DEMUXER)               += flvdec.o
+OBJS-$(CONFIG_LIVE_FLV_DEMUXER)          += flvdec.o
 OBJS-$(CONFIG_FLV_MUXER)                 += flvenc.o avc.o
 OBJS-$(CONFIG_FOURXM_DEMUXER)            += 4xm.o
 OBJS-$(CONFIG_FRAMECRC_MUXER)            += framecrcenc.o framehash.o