[PATCH] USB Storage: retry hard errors

This patch started life as as527, and was rediffed by me.

Since the IDE interface doesn't convey much information about types of
errors, many USB-IDE adapters report all low-level errors with SK = 0x04,
which is supposed to be used only for non-recoverable errors.  As a result
the SCSI midlayer doesn't retry the command.  But quite often a retry
would succeed, whereas an unnecessary retry doesn't really hurt anything.

This patch uses a recently-implemented flag to tell the SCSI midlayer that
such hardware errors should be retried.

Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Matthew Dharm <mdharm-usb@one-eyed-alien.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>