Revert revert of "[SCSI] fix usb storage oops"

This reverts commit 1b0997f5, which in
turn reverted 34ea80ec (which is thus
re-instated).

Quoth James Bottomley:

  "All it's doing is deferring the device_put() from the
   scsi_put_command() to after the scsi_run_queue(), which doesn't fix
   the sleep while atomic problem of the device release method.  In both
   cases we still get the semaphore in atomic context problem which is
   caused by scsi_reap_target() doing a device_del(), which I assumed
   (wrongly) was valid from atomic context."

who also promised to fix scsi_reap_target().

Signed-off-by: Linus Torvalds <torvalds@osdl.org>