netdev-bsd: Update for recent ofpbuf api changes

Leftovers from commit commit 1f317cb5.
("ofpbuf: Introduce access api for base, data and size.")

This fixes regressons introduced by commit 3f976e12.
("lib/ofpbuf: Rename private fields to discourage direct use.")

Acked-by: Ben Pfaff <blp@nicira.com>
Signed-off-by: YAMAMOTO Takashi <yamamoto@valinux.co.jp>
learn.at: Fix a shell syntax

Fix a botch in commit 7f12bdcc.
("learn.at: Fix a race in "self-modifying flow with idle_timeout" test")

Acked-by: Ben Pfaff <blp@nicira.com>
Signed-off-by: YAMAMOTO Takashi <yamamoto@valinux.co.jp>