bionic libc test: clean up sysconf test

After migrated the sysconf tests in file
    tests/bionic/libc/other/test_sysconf.c
to file bionic/tests/unistd_test.cpp,

clean up the test implementation files and settings here.

Change-Id: I1a29047e462d8e423c4125d6cb50634049b296ef
Signed-off-by: Yongqin Liu <yongqin.liu@linaro.org>
2 files changed