[S390] Get rid of a lot of sparse warnings.

Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
diff --git a/arch/s390/mm/init.c b/arch/s390/mm/init.c
index 4bb21be..6315f75 100644
--- a/arch/s390/mm/init.c
+++ b/arch/s390/mm/init.c
@@ -25,6 +25,7 @@
 #include <linux/bootmem.h>
 #include <linux/pfn.h>
 #include <linux/poison.h>
+#include <linux/initrd.h>
 
 #include <asm/processor.h>
 #include <asm/system.h>
@@ -107,8 +108,6 @@
 	}
 }
 
-extern void vmem_map_init(void);
-
 /*
  * paging_init() sets up the page tables
  */