idr: describe how nextidp works in idr_get_next().
idr: describe how nextidp works in idr_get_next().

It was unclear in original kernel-doc how nextidp worked in
idr_get_next(). Let's describe it.

Signed-off-by: Naohiro Aota <84c9fc2bcc4675501be1b557d5ef1e0e073dbf3e@elisp.net>
Acked-by: Tejun Heo <546b05909706652891a87f7bfe385ae147f61f91@kernel.org>
Signed-off-by: Jiri Kosina <ed58f755cc8caaf10c3e8c731a8b86fb8f13d6cb@suse.cz>

KristFoundation/Programs,KristFoundation/Programs,TeamVee-Kanas/android_kernel_samsung_kanas,TeamVee-Kanas/android_kernel_samsung_kanas,TeamVee-Kanas/android_kernel_samsung_kanas,KristFoundation/Programs,TeamVee-Kanas/android_kernel_samsung_kanas,KristFoundation/Programs,KristFoundation/Programs,TeamVee-Kanas/android_kernel_samsung_kanas,KristFoundation/Programs