rist: remove nonexistent Makefile variable

modules/access/Makefile.am

@@ -459,7 +459,7 @@ EXTRA_LTLIBRARIES += libaccess_srt_plugin.la
 
 librist_plugin_la_SOURCES = access/rist.c access/rist.h
 librist_plugin_la_CFLAGS = $(AM_CFLAGS) $(RIST_CFLAGS)
-librist_plugin_la_LIBADD = $(RIST_LIBS) $(SOCKET_LIBS) $(LIBPTHREAD)
+librist_plugin_la_LIBADD = $(RIST_LIBS) $(SOCKET_LIBS)
 librist_plugin_la_LDFLAGS = $(AM_LDFLAGS) -rpath '$(accessdir)'
 access_LTLIBRARIES += $(LTLIBrist)
 EXTRA_LTLIBRARIES += librist_plugin.la

modules/access_output/Makefile.am

@@ -41,7 +41,7 @@ EXTRA_LTLIBRARIES += libaccess_output_srt_plugin.la
 
 libaccess_output_rist_plugin_la_SOURCES = access_output/rist.c
 libaccess_output_rist_plugin_la_CFLAGS = $(AM_CFLAGS) $(RIST_CFLAGS)
-libaccess_output_rist_plugin_la_LIBADD = $(RIST_LIBS) $(SOCKET_LIBS) $(LIBPTHREAD)
+libaccess_output_rist_plugin_la_LIBADD = $(RIST_LIBS) $(SOCKET_LIBS)
 libaccess_output_rist_plugin_la_LDFLAGS = $(AM_LDFLAGS) -rpath '$(access_outdir)'
 access_out_LTLIBRARIES += $(LTLIBaccess_output_rist)
 EXTRA_LTLIBRARIES += libaccess_output_rist_plugin.la