bionic libc test: clean up dlclose related test in system/extras

The dlclose related tests are re-implemented in bionic/tests/atexit_test.cpp
These files are no need to be here.

Change-Id: I8da70ed2ac12d639f737d83476d1614f8d560410
Signed-off-by: Yongqin Liu <yongqin.liu@linaro.org>
4 files changed