Fix Xvnc dependency list (again)

The previous commit was incorrect in that it overrides automake's
dependency list, rather than adding to it. So we need to make sure
things are duplicated between Xvnc_DEPENDENCIES and Xvnc_LDADD as
appropriate.

Use the same approach as the Xorg binary to keep things familiar.

unix/xserver/hw/vnc/Makefile.am

@@ -44,9 +44,14 @@ Xvnc_CPPFLAGS = $(XVNC_CPPFLAGS) -DTIGERVNC -DNO_MODULE_EXTS \
 	-DVENDOR_STRING="\"$(VENDOR_STRING)\"" -I$(TIGERVNC_SRCDIR)/common -I$(TIGERVNC_SRCDIR)/unix/common \
 	-I$(top_srcdir)/include ${XSERVERLIBS_CFLAGS}
 
-Xvnc_DEPENDENCIES = $(XVNC_LIBS) $(XSERVER_LIBS)
-Xvnc_LDADD = $(XVNC_LIBS) libvnccommon.la $(COMMON_LIBS) \
-	$(XSERVER_LIBS) $(XSERVER_SYS_LIBS) $(XVNC_SYS_LIBS) -lX11
+LOCAL_LIBS = \
+	$(XVNC_LIBS) \ \
+	$(XSERVER_LIBS) \
+	libvnccommon.la \
+	$(COMMON_LIBS)
+
+Xvnc_DEPENDENCIES = $(LOCAL_LIBS)
+Xvnc_LDADD = $(LOCAL_LIBS) $(XSERVER_SYS_LIBS) $(XVNC_SYS_LIBS) -lX11
 
 Xvnc_LDFLAGS = $(LD_EXPORT_SYMBOLS_FLAG)