i2c: amd-mp2-pci: Fix Oops in amd_mp2_pci_init() error handling

The problem is that we dereference "privdata->pci_dev" when we print
the error messages in amd_mp2_pci_init():

	dev_err(ndev_dev(privdata), "Failed to enable MP2 PCI device\n");
		^^^^^^^^^^^^^^^^^

Fixes: 529766e0

 ("i2c: Add drivers for the AMD PCIe MP2 I2C controller")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Cc: stable@kernel.org