ksmbd: 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.

Note that the upper limit of ida_simple_get() is exclusive, but the one of
ida_alloc_range() is inclusive. So change a 0xFFFFFFFF into a 0xFFFFFFFE in
order to keep the same behavior.

Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
Acked-by: Namjae Jeon <linkinjeon@kernel.org>
Signed-off-by: Steve French <stfrench@microsoft.com>