Avoid burn stack in Arcfour setkey
* cipher/arcfour.c (arcfour_setkey): Remove stack burning.
Stack is already cleared in do_arcfour_setkey and GCC is inlining
do_arcfour_setkey to arcfour_setkey which renders this _gcry_burn_stack
broken anyways.
- Signed-off-by: Jussi Kivilinna <jussi.kivilinna@iki.fi>