[PATCH] uml: fix 2 harmless cast warnings for 64-bit

Fix two harmless warnings in 64-bit compilation (the 2nd doesn't trigger for
now because of a missing __attribute((format)) for cow_printf, but next
patches fix that).

Signed-off-by: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
Cc: Jeff Dike <jdike@addtoit.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
diff --git a/arch/um/drivers/cow_user.c b/arch/um/drivers/cow_user.c
index a9afccf..0ec4052 100644
--- a/arch/um/drivers/cow_user.c
+++ b/arch/um/drivers/cow_user.c
@@ -210,8 +210,9 @@
 
 	err = -EINVAL;
 	if(strlen(backing_file) > sizeof(header->backing_file) - 1){
+		/* Below, %zd is for a size_t value */
 		cow_printf("Backing file name \"%s\" is too long - names are "
-			   "limited to %d characters\n", backing_file,
+			   "limited to %zd characters\n", backing_file,
 			   sizeof(header->backing_file) - 1);
 		goto out_free;
 	}