[SCSI] Increase default timeout for INQUIRY

This patch (as1224) changes the default timeout for INQUIRY commands
from 3 seconds to 20 seconds, which is the value used by Windows for
USB Mass-Storage devices.  Some of these devices, like the Corsair
Flash Voyager (see Bugzilla #12188) really do need a long timeout.

Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>