VMXNET3: Check for map error in vmxnet3_set_mc

We should check if the map of the table actually succeeds, and also free
resources accordingly.

Version bumped to 1.2.1.0

Acked-by: Shelley Gong <shelleygong@vmware.com>
Acked-by: Bhavesh Davda <bhavesh@vmware.com>
Signed-off-by: Andy King <acking@vmware.com>
Reported-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Signed-off-by: David S. Miller <davem@davemloft.net>