Staging: hv: storvsc: Move and cleanup storvsc_remove()

Relocate the storvsc_remove() function to a different location in the file
and invoke scsi_host_put() only after all the cleanup.

Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>