ramoops: update parameters only after successful init

If a platform device exists on the system, but ramoops fails to attach to
it, the module parameters are overridden before ramoops can fall back and
try to use passed module parameters.  Move update to end of init routine.

Signed-off-by: Kees Cook <keescook@chromium.org>
Cc: Marco Stornelli <marco.stornelli@gmail.com>
Cc: Sergiu Iordache <sergiu@chromium.org>
Cc: Seiji Aguchi <seiji.aguchi@hds.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>