lua: fix non-shared library build

Building without BR2_PACKAGE_LUA_SHARED_LIBRARY failed because of
missing -ldl.  dl is used by lua's dynamic module loading.

Signed-off-by: Arnout Vandecappelle (Essensium/Mind) <arnout@mind.be>
Acked-by: Gustavo Zacarias <gustavo@zacarias.com.ar>
Signed-off-by: Peter Korsgaard <jacmet@sunsite.dk>

package/lua/lua.mk

@@ -10,9 +10,10 @@ LUA_INSTALL_STAGING = YES
 
 ifeq ($(BR2_PACKAGE_LUA_SHARED_LIBRARY),y)
 	LUA_MYCFLAGS += -fPIC
-	LUA_MYLIBS += -ldl
 endif
 
+LUA_MYLIBS += -ldl
+
 ifeq ($(BR2_PACKAGE_LUA_INTERPRETER_READLINE),y)
 	LUA_DEPENDENCIES = readline ncurses
 	LUA_MYLIBS += -lreadline -lhistory -lncurses