net/vmxnet3: return 1 on device activation failure

When reading device status, 0 means device is successfully
activated and 1 means error.

This behavior can be observed by the following steps:

1) run a Linux distro on esxi server (5.5+)
2) modify vmxnet3 Linux driver to give it an invalid
   address to 'adapter->shared_pa' which is the
   shared memory for guest/host communication

This will trigger device activation failure and kernel
log will have the following message:

   [ 7138.403256] vmxnet3 0000:03:00.0 eth1: Failed to activate dev: error 1

So return 1 on device activation failure instead of -1;

Signed-off-by: Miao Yan <yanmiaobest@gmail.com>
Reviewed-by: Dmitry Fleytman <dmitry@daynix.com>
Signed-off-by: Jason Wang <jasowang@redhat.com>
