ipv6 addrconf: Introduce addrconf_is_prefix_route() helper.
ipv6 addrconf: Introduce addrconf_is_prefix_route() helper.

This inline function, for readability, returns if the route
is a "prefix" route regardless if it was installed by RA or by
hand.

Signed-off-by: YOSHIFUJI Hideaki <948b80da4254122ea1e8973dd9930d46b7654cf3@linux-ipv6.org>

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