Current user_buffer check is incorrect and causes hdparm to fail
# hdparm -I /dev/rssda
 HDIO_DRIVE_CMD(identify) failed: Input/output error
/dev/rssda:
Patching linux-3.6-rc5 hdparm works as expected
# hdparm -I /dev/rssda
/dev/rssda:
ATA device, with non-removable media
	Model Number:       DELL_P320h-MTFDGAL350SAH
	Serial Number:      
00000000121302025F01
	Firmware Revision:  
B1442808
<snip>
Reported-by: Tomas Henzl <thenzl@redhat.com>
Signed-off-by: David Milburn <dmilburn@redhat.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
 
        int rv = 0, xfer_sz = command[3];
 
        if (xfer_sz) {
-               if (user_buffer)
+               if (!user_buffer)
                        return -EFAULT;
 
                buf = dmam_alloc_coherent(&port->dd->pdev->dev,