test/dlopen: fix build for libtest.so

needs -lpthread, recent addition of -z,defs and -z,now exposed this

Signed-off-by: Austin Foxley <austinf@cetoncorp.com>

test/dlopen/Makefile.in

@@ -33,6 +33,7 @@ test1: libtest1.so
 test2: libtest1.so libtest2.so
 test3: libtest1.so libtest2.so
 libtest1.so: libtest2.so
+LDFLAGS_libtest.so := -lpthread
 LDFLAGS_libtest1.so := ./libtest2.so -Wl,-rpath,.
 LDFLAGS_libtest2.so := -Wl,-rpath,.
 LDFLAGS_libtest3.so := -lpthread -Wl,-rpath,.