powerpc/pci: Fix unmapping of IO space on 64-bit

A typo/thinko made us pass the wrong argument to __flush_hash_table_range
when unplugging bridges, thus not flushing all the translations for
the IO space on unplug.  The third parameter to __flush_hash_table_range
is `end', not `size'.

This causes the hypervisor to refuse unplugging slots.

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>
diff --git a/arch/powerpc/kernel/pci_64.c b/arch/powerpc/kernel/pci_64.c
index 8247cff..3502b91 100644
--- a/arch/powerpc/kernel/pci_64.c
+++ b/arch/powerpc/kernel/pci_64.c
@@ -426,7 +426,7 @@
 		    pci_name(bus->self));
 
 		__flush_hash_table_range(&init_mm, res->start + _IO_BASE,
-					 res->end - res->start + 1);
+					 res->end + _IO_BASE + 1);
 		return 0;
 	}