[SCSI] Don't attempt to send extended INQUIRY command if skip_vpd_pages is set

If a device has the skip_vpd_pages flag set we should simply fail the
scsi_get_vpd_page() call.

Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Acked-by: Alan Stern <stern@rowland.harvard.edu>
Tested-by: Stuart Foster <smf.linux@ntlworld.com>
Cc: stable@vger.kernel.org
Signed-off-by: James Bottomley <JBottomley@Parallels.com>