Revert "can: ti_hecc: fix -Woverflow compiler warning"

This reverts commit 1da38b70 which is
commit 7cae4d04 upstream.

It breaks the arm kernel build and will be reverted upstream.

Bug: 161946584
Change-Id: I1a21e89d8c9ae4d08a13b0a287be970ca1983bbc
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>