MT#61993 build: Do not query LDLIBS from dpkg-buildflags

This variable is unknown to dpkg-buildflags. This also reduces the
amount of global calls generated with GNU make 4.4 (which has a
regression causing massive amounts of shell calls to be generated).

Change-Id: Ia9d7099228bf5e181df4725939ed4f76f1e63dc9
(cherry picked from commit bb2bf3a702)

lib/lib.Makefile

@@ -68,7 +68,6 @@ ifneq ($(DBG),yes)
       CFLAGS+=	$(shell dpkg-buildflags --get CFLAGS)
       CPPFLAGS+=	$(shell dpkg-buildflags --get CPPFLAGS)
       LDFLAGS+=	$(shell dpkg-buildflags --get LDFLAGS)
-      LDLIBS+=	$(shell dpkg-buildflags --get LDLIBS)
     endif
     CFLAGS+=-O3 -flto=auto -ffat-lto-objects
     LDFLAGS+=-flto=auto