[PATCH] Don't #ifdef prototypes

It seems that changing CONFIG_BLK_DEV_INITRD causes the whole kernel to
rebuild due to an inappropriate ifdef in linux/fs.h - we should not
conditionalise prototypes.

In addition, real_root_dev is only used by two files (kernel/sysctl.c
and init/do_mounts_initrd.c) so it makes even less sense that it was in
linux/fs.h

include/linux/fs.h

@@ -1391,10 +1391,6 @@ extern int simple_fill_super(struct super_block *, int, struct tree_descr *);
 extern int simple_pin_fs(char *name, struct vfsmount **mount, int *count);
 extern void simple_release_fs(struct vfsmount **mount, int *count);
 
-#ifdef CONFIG_BLK_DEV_INITRD
-extern unsigned int real_root_dev;
-#endif
-
 extern int inode_change_ok(struct inode *, struct iattr *);
 extern int inode_setattr(struct inode *, struct iattr *);
 

include/linux/initrd.h

@@ -16,3 +16,5 @@ extern int initrd_below_start_ok;
 /* free_initrd_mem always gets called with the next two as arguments.. */
 extern unsigned long initrd_start, initrd_end;
 extern void free_initrd_mem(unsigned long, unsigned long);
+
+extern unsigned int real_root_dev;

kernel/sysctl.c

@@ -35,6 +35,7 @@
 #include <linux/writeback.h>
 #include <linux/hugetlb.h>
 #include <linux/security.h>
+#include <linux/initrd.h>
 #include <asm/uaccess.h>
 
 #ifdef CONFIG_ROOT_NFS