xen/pciback: Fix incorrect type warnings

Correct enum pci_channel_io_normal should be used instead of putting
integer value 1.

Fix following smatch warnings:
drivers/xen/xen-pciback/pci_stub.c:805:40: warning: incorrect type in argument 2 (different base types)
drivers/xen/xen-pciback/pci_stub.c:805:40:    expected restricted pci_channel_state_t [usertype] state
drivers/xen/xen-pciback/pci_stub.c:805:40:    got int
drivers/xen/xen-pciback/pci_stub.c:862:40: warning: incorrect type in argument 2 (different base types)
drivers/xen/xen-pciback/pci_stub.c:862:40:    expected restricted pci_channel_state_t [usertype] state
drivers/xen/xen-pciback/pci_stub.c:862:40:    got int
drivers/xen/xen-pciback/pci_stub.c:973:31: warning: incorrect type in argument 2 (different base types)
drivers/xen/xen-pciback/pci_stub.c:973:31:    expected restricted pci_channel_state_t [usertype] state
drivers/xen/xen-pciback/pci_stub.c:973:31:    got int

Signed-off-by: Muhammad Usama Anjum <musamaanjum@gmail.com>
Reviewed-by: Juergen Gross <jgross@suse.com>
Link: https://lore.kernel.org/r/20210326181442.GA1735905@LEGION
Signed-off-by: Juergen Gross <jgross@suse.com>

drivers/xen/xen-pciback/pci_stub.c

@@ -802,7 +802,7 @@ static pci_ers_result_t xen_pcibk_slot_reset(struct pci_dev *dev)
 			"guest with no AER driver should have been killed\n");
 		goto end;
 	}
-	result = common_process(psdev, 1, XEN_PCI_OP_aer_slotreset, result);
+	result = common_process(psdev, pci_channel_io_normal, XEN_PCI_OP_aer_slotreset, result);
 
 	if (result == PCI_ERS_RESULT_NONE ||
 		result == PCI_ERS_RESULT_DISCONNECT) {
@@ -859,7 +859,7 @@ static pci_ers_result_t xen_pcibk_mmio_enabled(struct pci_dev *dev)
 			"guest with no AER driver should have been killed\n");
 		goto end;
 	}
-	result = common_process(psdev, 1, XEN_PCI_OP_aer_mmio, result);
+	result = common_process(psdev, pci_channel_io_normal, XEN_PCI_OP_aer_mmio, result);
 
 	if (result == PCI_ERS_RESULT_NONE ||
 		result == PCI_ERS_RESULT_DISCONNECT) {
@@ -970,7 +970,7 @@ static void xen_pcibk_error_resume(struct pci_dev *dev)
 		kill_domain_by_device(psdev);
 		goto end;
 	}
-	common_process(psdev, 1, XEN_PCI_OP_aer_resume,
+	common_process(psdev, pci_channel_io_normal, XEN_PCI_OP_aer_resume,
 		       PCI_ERS_RESULT_RECOVERED);
 end:
 	if (psdev)