Staging: hv: storvsc: Cleanup storvsc_queuecommand()

Cleanup storvsc_queuecommand(). As part of this cleanup, rename the function to
check if the scsi command can be sent to the host, consolidate error recovery
and get rid of some dead code.

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