Staging: hv: netvsc_drv: Get rid of unused state in struct netvsc_driver

Staging: hv: netvsc_drv: Get rid of unused state in struct netvsc_driver

In preparation to getting rid of struct netvsc_driver, get rid of the
unused state (void *ctx)  in struct netvsc_driver.

Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: Haiyang Zhang <haiyangz@microsoft.com>
Signed-off-by: Abhishek Kane <v-abkane@microsoft.com>
Signed-off-by: Hank Janssen <hjanssen@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>