8411 Build should warn when linking against libraries outside proto area

@@ -23,10 +23,11 @@
 # Use is subject to license terms.
 #
 
 #
 # Copyright (c) 2012 by Delphix. All rights reserved.
+# Copyright 2017 RackTop Systems.
 #
 
 PROG = isns
 
 DSRC = isns_provider.d

@@ -68,10 +69,13 @@
 obj.o := CERRWARN += -erroff=E_CONST_OBJ_SHOULD_HAVE_INITIZR
 obj.o := CERRWARN += -erroff=E_IMPLICIT_DECL_FUNC_RETURN_INT
 
 LDLIBS          += -lsecdb -lsocket -lnsl -lscf -lxml2
 
+# Allow libxml2 to be taken from outside the proto area.
+$(ADJUNCT_PROTO_NOT_SET)LDFLAGS += $(ZASSERTDEFLIB)=libxml2.so
+
 .KEEP_STATE:
 
 all:    $(PROG)
 
 $(PROG): $(OBJS)