PCI: Update pci_find_slot() description in pci.txt

pci_find_slot() has been removed from the kernel.  Document its
closest replacement, pci_get_domain_bus_and_slot(), instead.

[bhelgaas: fix indentation, keep mention in "obsolete" section]
Signed-off-by: NYijing Wang <wangyijing@huawei.com>
Signed-off-by: NBjorn Helgaas <bhelgaas@google.com>

Documentation/PCI/pci.txt

@@ -525,8 +525,9 @@ corresponding register block for you.
 6. Other interesting functions
 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 
-pci_find_slot()			Find pci_dev corresponding to given bus and
-				slot numbers.
+pci_get_domain_bus_and_slot()	Find pci_dev corresponding to given domain,
+				bus and slot and number. If the device is
+				found, its reference count is increased.
 pci_set_power_state()		Set PCI Power Management state (0=D0 ... 3=D3)
 pci_find_capability()		Find specified capability in device's capability
 				list.
@@ -582,7 +583,8 @@ having sane locking.
 
 pci_find_device()	Superseded by pci_get_device()
 pci_find_subsys()	Superseded by pci_get_subsys()
-pci_find_slot()		Superseded by pci_get_slot()
+pci_find_slot()		Superseded by pci_get_domain_bus_and_slot()
+pci_get_slot()		Superseded by pci_get_domain_bus_and_slot()
 
 
 The alternative is the traditional PCI device driver that walks PCI