Prior to this change, a missing loop bounds check in the aarch64
version of gf_vect_mul would cause the routine to return 1 (error)
in the normal case.
This change introduces a check and branch to "return_pass" (success), and
also adds checks of the return code of gf_vect_mul to the supplied unit
test; it was previously ignored.
Change-Id: I9f7fe0014189b24f9600e0473ee02b5316c2da91
Signed-off-by: Surendar Chandra <vsurench@amazon.com>