tools/xenstore: add libdl dependency to libxenstore

Commit 448c03b3cb ("tools/xenstore: try to get minimum thread
stack size for watch thread") added a dependency to libdl to
libxenstore.

Add the needed flags to LDLIBS_libxenstore and the pkg-config file of
libxenstore.

Fixes: 448c03b3cb
Signed-off-by: Juergen Gross <jgross@suse.com>
Acked-by: Wei Liu <wei.liu2@citrix.com>

tools/Rules.mk

@@ -149,6 +149,9 @@ CFLAGS_libxenstore = -I$(XEN_XENSTORE)/include $(CFLAGS_xeninclude)
 SHDEPS_libxenstore = $(SHLIB_libxentoolcore)
 LDLIBS_libxenstore = $(SHDEPS_libxenstore) $(XEN_XENSTORE)/libxenstore$(libextension)
 SHLIB_libxenstore  = $(SHDEPS_libxenstore) -Wl,-rpath-link=$(XEN_XENSTORE)
+ifeq ($(CONFIG_Linux),y)
+LDLIBS_libxenstore += -ldl
+endif
 
 CFLAGS_libxenstat  = -I$(XEN_LIBXENSTAT)
 SHDEPS_libxenstat  = $(SHLIB_libxenctrl) $(SHLIB_libxenstore)