Release resources when repeating dlopen-dlcose.

When the libbinder.so is dlopen and dlclose many
times, we need to delete the pthread_key and
munmap the memory mapping.

Otherwise, it will crash as the leakage causes
the pthread_key or memory mapping surpass their
limit.

Change-Id: Ice64d4ef685c1f665350286f9e5ddf790beac236
Signed-off-by: zhongjie <zhongjie.shi@intel.com>