Staging: hv: hv_mouse: get rid of hungarian notation for name of the module

And, it's not even a global, so the original creator got the Hungarian
notation wrong!  {sigh}

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