When the static_key is part of the module, and the module calls
static_key_inc/enable() from it's __init section *AND* has a
static_branch_*() user in that very same __init section, things go
wobbly.

If the static_key lives outside the module, jump_label_add_module()
would append this module's sites to the key and jump_label_update()
would take the static_key_linked() branch and all would be fine.

If all the sites are outside of __init, then everything will be fine
too.

However, when all is aligned just as described above,
jump_label_update() calls __jump_label_update(.init = false) and we'll
not update sites in __init text.

Fixes: 19483677 ("jump_label: Annotate entries that operate on __init code earlier")
Reported-by: Dexuan Cui <decui@microsoft.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Josh Poimboeuf <jpoimboe@redhat.com>
Tested-by: Jessica Yu <jeyu@kernel.org>
Link: https://lkml.kernel.org/r/20201216135435.GV3092@hirez.programming.kicks-ass.net