lib/devres.c: fix checkpatch warnings

Fix 3 checkpatch warnings:
'ERROR: "foo * const * bar" should be "foo * const *bar"'

Cc: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Fabian Frederick <fabf@skynet.be>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>