lib: ubsan: Fix compilation issues for ubsan

Currently, multiple declarations of data structures and
functions exist, as well as dead code that was meant to be
removed earlier. Remove dead code and multiple declarations
for ubsan.

Change-Id: I2b1d27ab2edc9852a3cd286c70fe8990aa0e0754
Signed-off-by: Isaac J. Manjarres <isaacm@codeaurora.org>