Replace dl linking with cmake-based variable

Signed-off-by: Michele Calgaro <michele.calgaro@yahoo.it>

ConfigureChecks.cmake

@@ -39,15 +39,7 @@ if( WITH_LIBLTDL )
 
 else( WITH_LIBLTDL )
     # check libdl
-    set( AKODE_LIBDL dl )
-    check_library_exists( ${AKODE_LIBDL} dlopen /lib HAVE_LIBDL )
-    if( NOT HAVE_LIBDL )
-        unset( AKODE_LIBDL )
-        check_function_exists( dlopen HAVE_DLOPEN )
-        if( NOT HAVE_DLOPEN )
-            tde_message_fatal( "libdl are required, but not found on your system" )
-        endif( NOT HAVE_DLOPEN )
-    endif( NOT HAVE_LIBDL )
+    set( AKODE_LIBDL ${CMAKE_DL_LIBS} )
 endif( WITH_LIBLTDL )