mfd: sta2x11-mfd: Only add sta2x11_mfd if it hasn't already been added

The pci probe method is called twice now, so we have to call
sta2x11_mfd_add() only once to avoid a -EBUSY error.
Signed-off-by: NDavide Ciminaghi <ciminaghi@gnudd.com>
Acked-by: NAlessandro Rubini <rubini@gnudd.com>
Signed-off-by: NSamuel Ortiz <sameo@linux.intel.com>

drivers/mfd/sta2x11-mfd.c

@@ -585,7 +585,8 @@ static int __devinit sta2x11_mfd_probe(struct pci_dev *pdev,
 	sta2x11_mfd_setup(pdev, setup_data);
 
 	/* Record this pdev before mfd_add_devices: their probe looks for it */
-	sta2x11_mfd_add(pdev, GFP_ATOMIC);
+	if (!sta2x11_mfd_find(pdev))
+		sta2x11_mfd_add(pdev, GFP_ATOMIC);
 
 	/* Just 2 bars for all mfd's at present */
 	for (i = 0; i < 2; i++) {