[PATCH] ibmveth fix panic in initial replenish cycle

This patch fixes a panic in the current tree caused by a race condition between the initial replenish cycle and the rx processing of the first packets trying to replenish the buffers.

Signed-off-by: Santiago Leon <santil@us.ibm.com>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>