tools lib traceevent: Use LDFLAGS in the build commands

So that the user can specify outside LDFLAGS values.

Keeping the CFLAGS in there as well, so we don't break existing scripts.
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Acked-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Cc: Herton Krzesinski <herton@redhat.com>
Cc: Tzvetomir Stoyanov (VMware) <tz.stoyanov@gmail.com>
Link: http://lkml.kernel.org/r/20181212091214.GC17489@kravaSigned-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

tools/lib/traceevent/Makefile

@@ -177,7 +177,7 @@ $(TE_IN): force
 	$(Q)$(MAKE) $(build)=libtraceevent
 
 $(OUTPUT)libtraceevent.so.$(EVENT_PARSE_VERSION): $(TE_IN)
-	$(QUIET_LINK)$(CC) --shared $^ -Wl,-soname,libtraceevent.so.$(EP_VERSION) -o $@
+	$(QUIET_LINK)$(CC) --shared $(LDFLAGS) $^ -Wl,-soname,libtraceevent.so.$(EP_VERSION) -o $@
 	@ln -sf $(@F) $(OUTPUT)libtraceevent.so
 	@ln -sf $(@F) $(OUTPUT)libtraceevent.so.$(EP_VERSION)
 
@@ -196,7 +196,7 @@ $(PLUGINS_IN): force
 	$(Q)$(MAKE) $(build)=$(plugin_obj)
 
 $(OUTPUT)%.so: $(OUTPUT)%-in.o
-	$(QUIET_LINK)$(CC) $(CFLAGS) -shared -nostartfiles -o $@ $^
+	$(QUIET_LINK)$(CC) $(CFLAGS) -shared $(LDFLAGS) -nostartfiles -o $@ $^
 
 define make_version.h
   (echo '/* This file is automatically generated. Do not modify. */';		\