Register window saving loop in __sigsetjmp incorrectly calculates offset
in the jmp_buf in case it was called with call12. The bug was introduced
in commit f4b1b7ade7971141 "xtensa: fix setjmp that didn't save all
registers correctly".
Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
Max Filippov