random: only call boot_init_stack_canary() once

In commit 166a592c ("random: move rand_initialize() earlier") the
boot_init_stack_canary() call was added after the new random_init()
call.

However, the upstream commit d55535232c3d ("random: move
rand_initialize() earlier") also included removing the earlier call to
boot_init_stack_canary(), making sure this call is done after
random_init().

Hence fix what I assume is a wrong merge conflict resolution on the
linux-4.9.y stable branch.

Signed-off-by: Hans-Christian Noren Egtvedt <hegtvedt@cisco.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>