Remove explicit check for libdl

configure.ac

@@ -403,13 +403,6 @@ AS_IF([test "x$squid_opt_aufs_threads" != "x"],[
     [Defines how many threads aufs uses for I/O])
 ])
 
-## TODO check if this is necessary, LT_INIT does these checks
-SQUID_AUTO_LIB(dl,[dynamic linking],[LIBDL])
-SQUID_CHECK_LIB_WORKS(dl,[
-  LDFLAGS="$LIBDL_PATH $LDFLAGS"
-  AC_CHECK_LIB(dl, dlopen,[LIBDL_LIBS="-ldl"])
-])
-
 AC_DEFUN([LIBATOMIC_CHECKER],[
   AC_MSG_CHECKING(whether linking $1 -latomic works)
   AC_LINK_IFELSE([