Make s390 and s390x print the right freed init memory size.

The expression (&__init_begin - &__init_end) depends on the type
of this adhoc extern variables, which was changed from char to long
when the code was copied from another arch.

arch/s390/mm/init.c

@@ -189,7 +189,7 @@ void free_initmem(void)
 		totalram_pages++;
         }
         printk ("Freeing unused kernel memory: %dk freed\n",
-		(&__init_end - &__init_begin) >> 10);
+		((unsigned long)&__init_end - (unsigned long)&__init_begin) >> 10);
 }
 
 #ifdef CONFIG_BLK_DEV_INITRD

arch/s390x/mm/init.c

@@ -201,7 +201,7 @@ void free_initmem(void)
 		totalram_pages++;
         }
         printk ("Freeing unused kernel memory: %ldk freed\n",
-		(&__init_end - &__init_begin) >> 10);
+		((unsigned long)&__init_end - (unsigned long)&__init_begin) >> 10);
 }
 
 #ifdef CONFIG_BLK_DEV_INITRD