[PATCH] PCI: fix sparse warning about pci_bus_flags

Sparse warns about casting to a __bitwise type.  However, it's correct
to do when defining the enum for pci_bus_flags_t, so add a __force to
quiet the warnings.  This will fix getting

    include/linux/pci.h:100:26: warning: cast to restricted type

from sparse all over the build.
Signed-off-by: Roland Dreier <rolandd@cisco.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

include/linux/pci.h

@@ -97,7 +97,7 @@ enum pci_channel_state {
 
 typedef unsigned short __bitwise pci_bus_flags_t;
 enum pci_bus_flags {
-	PCI_BUS_FLAGS_NO_MSI = (pci_bus_flags_t) 1,
+	PCI_BUS_FLAGS_NO_MSI = (__force pci_bus_flags_t) 1,
 };
 
 struct pci_cap_saved_state {