rpmb: Remove usage of the deprecated ida_simple_xx() API

ida_alloc() and ida_free() should be preferred to the deprecated
ida_simple_get() and ida_simple_remove().

This is less verbose.

Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
Link: https://lore.kernel.org/r/df8bfbe2a603c596566a4f967e37d10d208bbc3f.1728507153.git.christophe.jaillet@wanadoo.fr


Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>