Clear up unused variable in bionic

Change-Id: I5e8a599ddd8df6f43d5d7a86db0cf09fb8a9aa8d
Add malloc implmentation without malloc debug feature

 - Code can be reduce about 4k in arm.
Hidden dlmalloc family functions for libc.so and libc.a

 - Those functions are internal use only for libc.so and libc.a
   in malloc_debug_common.c.

Change-Id: I54ac3717b08c5b7ef01a1ddeb7945f22577f3608