The pstore subsystem already had a private version of this function.
With the coming addition of the pstore/zone driver, this needs to be
shared. As it really should live with printk, move it there instead.

Link: https://lore.kernel.org/lkml/20200515184434.8470-4-keescook@chromium.org/Acked-by: NPetr Mladek <pmladek@suse.com>
Acked-by: NSergey Senozhatsky <sergey.senozhatsky@gmail.com>
Reviewed-by: NPavel Tatashin <pasha.tatashin@soleen.com>
Signed-off-by: NKees Cook <keescook@chromium.org>