modplug: no need to link to stdc++ and m

This avoids extraneous libraries when libmodplug is a dynamic library.

configure.ac

@@ -620,7 +620,7 @@ AC_CHECK_FUNC(getopt_long,, [
 AC_SUBST(GNUGETOPT_LIBS)
 
 AC_CHECK_LIB(m,cos,[
-  VLC_ADD_LIBS([adjust wave ripple psychedelic gradient a52tofloat32 dtstofloat32 x264 goom visual panoramix rotate noise grain scene kate flac lua chorus_flanger freetype avcodec avformat access_avio swscale postproc i420_rgb faad twolame equalizer spatializer param_eq samplerate freetype mod mpc dmo mp4 quicktime qt4 compressor headphone_channel_mixer normvol audiobargraph_a speex mono colorthres extract ball access_imem hotkeys mosaic gaussianblur dbus x264 hqdn3d anaglyph],[-lm])
+  VLC_ADD_LIBS([adjust wave ripple psychedelic gradient a52tofloat32 dtstofloat32 x264 goom visual panoramix rotate noise grain scene kate flac lua chorus_flanger freetype avcodec avformat access_avio swscale postproc i420_rgb faad twolame equalizer spatializer param_eq samplerate freetype mpc dmo mp4 quicktime qt4 compressor headphone_channel_mixer normvol audiobargraph_a speex mono colorthres extract ball access_imem hotkeys mosaic gaussianblur dbus x264 hqdn3d anaglyph],[-lm])
   LIBM="-lm"
 ], [
   LIBM=""

modules/demux/Modules.am

@@ -12,7 +12,7 @@ SOURCES_live555 = live555.cpp ../access/mms/asf.c ../access/mms/buffer.c
 SOURCES_nsv = nsv.c
 SOURCES_real = real.c
 SOURCES_ps = ps.c ps.h
-SOURCES_mod = mod.c dummy.cpp
+SOURCES_mod = mod.c
 SOURCES_pva = pva.c
 SOURCES_aiff = aiff.c
 SOURCES_mjpeg = mjpeg.c mxpeg_helper.h