True, it's often used in return statements, but after much bikeshedding
it's probably better to have an explicit name.
(I tried just putting the IS_ERR check inside PTR_ERR itself and gcc
usually generated no more code. But that clashes current expectations
of how PTR_ERR behaves, so having a separate function is better).
Suggested-by: Julia Lawall <julia.lawall@lip6.fr> Suggested-by: "Michael S. Tsirkin" <mst@redhat.com> Cc: Julia Lawall <julia.lawall@lip6.fr> Cc: "Michael S. Tsirkin" <mst@redhat.com> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>