module: fix crash in get_ksymbol() when oopsing in module init

module: fix crash in get_ksymbol() when oopsing in module init

Andrew had the sole pleasure of tickling this bug in linux-next; when we set
up "info->strtab" it's pointing into the temporary copy of the module.  For
most uses that is fine, but kallsyms keeps a pointer around during module
load (inside mod->strtab).

If we oops for some reason inside a module's init function, kallsyms will use
the mod->strtab pointer into the now-freed temporary module copy.

(Later oopses work fine: after init we overwrite mod->strtab to point to a
 compacted core-only strtab).

Reported-by: Andrew "Grumpy" Morton <akpm@linux-foundation.org>
Signed-off-by: Rusty "Buggy" Russell <rusty@rustcorp.com.au>
Tested-by: Andrew "Happy" Morton <akpm@linux-foundation.org>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>