d_genocide(): move the extern into fs/internal.h

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
diff --git a/fs/internal.h b/fs/internal.h
index 9e9fc62..d9a920e 100644
--- a/fs/internal.h
+++ b/fs/internal.h
@@ -219,6 +219,7 @@ extern void shrink_dcache_for_umount(struct super_block *);
 extern struct dentry *__d_lookup(const struct dentry *, const struct qstr *);
 extern struct dentry *__d_lookup_rcu(const struct dentry *parent,
 				const struct qstr *name, unsigned *seq);
+extern void d_genocide(struct dentry *);
 
 /*
  * pipe.c