generic: make PFN_PHYS explicitly return phys_addr_t

PFN_PHYS, as its name suggests, turns a pfn into a physical address.
However, it is a macro which just operates on its argument without
modifying its type.  pfns are typed unsigned long, but an unsigned
long may not be long enough to hold a physical address (32-bit systems
with more than 32 bits of physcial address).

Make sure we cast to phys_addr_t to return a complete result.

Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
diff --git a/arch/m32r/mm/discontig.c b/arch/m32r/mm/discontig.c
index cbc3c4c..7daf897 100644
--- a/arch/m32r/mm/discontig.c
+++ b/arch/m32r/mm/discontig.c
@@ -111,9 +111,9 @@
 				initrd_start, INITRD_SIZE);
 		} else {
 			printk("initrd extends beyond end of memory "
-				"(0x%08lx > 0x%08lx)\ndisabling initrd\n",
+				"(0x%08lx > 0x%08llx)\ndisabling initrd\n",
 				INITRD_START + INITRD_SIZE,
-				PFN_PHYS(max_low_pfn));
+			        (unsigned long long)PFN_PHYS(max_low_pfn));
 
 			initrd_start = 0;
 		}