storvsc: Set the SRB flags correctly when no data transfer is needed

commit dc45708c upstream.

Set the SRB flags correctly when there is no data transfer.  Without this
change some IHV drivers will fail valid commands such as TEST_UNIT_READY.

Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Reviewed-by: Long Li <longli@microsoft.com>
Signed-off-by: James Bottomley <JBottomley@Odin.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>