VMCI: Fix an error handling path in vmci_guest_probe_device()

After a successful pci_iomap_range() call, pci_iounmap() should be called
in the error handling path, as already done in the remove function.

Add the missing call.

The corresponding call was added in the remove function in commit
5ee109828e73 ("VMCI: dma dg: allocate send and receive buffers for DMA
datagrams")

Fixes: e283a0e8b7ea ("VMCI: dma dg: add MMIO access to registers")
Signed-off-by: Christophe JAILLET <[e-mail]>
Acked-by: Vishnu Dasa <[e-mail]>
Link: https://lore.kernel.org/r/a35bbc3876[e-mail]
Signed-off-by: Greg Kroah-Hartman <[e-mail]>

drivers/misc/vmw_vmci/vmci_guest.c

···
 	if (!vmci_dev) {
 		dev_err(&pdev->dev,
 			"Can't allocate memory for VMCI device\n");
-		return -ENOMEM;
+		error = -ENOMEM;
+		goto err_unmap_mmio_base;
 	}
 
 	vmci_dev->dev = &pdev->dev;
···
 		if (!vmci_dev->tx_buffer) {
 			dev_err(&pdev->dev,
 				"Can't allocate memory for datagram tx buffer\n");
-			return -ENOMEM;
+			error = -ENOMEM;
+			goto err_unmap_mmio_base;
 		}
 
 		vmci_dev->data_buffer = dma_alloc_coherent(&pdev->dev, VMCI_DMA_DG_BUFFER_SIZE,
···
 
 err_free_data_buffers:
 	vmci_free_dg_buffers(vmci_dev);
+
+err_unmap_mmio_base:
+	if (mmio_base != NULL)
+		pci_iounmap(pdev, mmio_base);
 
 	/* The rest are managed resources and will be freed by PCI core */
 	return error;