examples: don't override LINK and other variables

Defining our own LINK causes us to run into some trouble with LDFLAGS,
which commit 16bb5c8075 already
demonstrated.

LDFLAGS does need to be included here, but it's probably even easier to
just use the default value.

https://bugzilla.gnome.org/show_bug.cgi?id=724195

examples/Makefile.am

@@ -1,11 +1,5 @@
 ## Process this file with automake to produce Makefile.in
 
-LINK			= $(LIBTOOL) --mode=link $(CC) $(CFLAGS) $(AM_LDFLAGS) -o $@
-
-INCLUDES		= @INCLUDES@
-
-DEFS			= @DEFS@
-
 AM_LDFLAGS			= $(LIBGTOP_EXTRA_LIBS)
 
 noinst_PROGRAMS	= 	first second pprint procargs df netlist \