Staging: hv: make RingInfo->RingLock a real spinlock

Staging: hv: make RingInfo->RingLock a real spinlock

Don't use the wrapper functions for this lock, make it a real
lock so that we know what is going on.

I don't think we really want to be doing a irqsave for this code, but I
left it alone to preserve the original codepath.  It should be reviewed
later.

Cc: Hank Janssen <hjanssen@microsoft.com>
Cc: Haiyang Zhang <haiyangz@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>