autofs: make autofs_expire_direct() static

autofs_expire_direct() isn't used outside of fs/autofs/expire.c so make it
static.

Link: http://lkml.kernel.org/r/152937732944.21213.11821977712410930973.stgit@pluto.themaw.net
Signed-off-by: Ian Kent <raven@themaw.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

fs/autofs/autofs_i.h

@@ -156,9 +156,6 @@ int autofs_do_expire_multi(struct super_block *sb, struct vfsmount *mnt,
 			   struct autofs_sb_info *sbi, int when);
 int autofs_expire_multi(struct super_block *, struct vfsmount *,
 			struct autofs_sb_info *, int __user *);
-struct dentry *autofs_expire_direct(struct super_block *sb,
-				    struct vfsmount *mnt,
-				    struct autofs_sb_info *sbi, int how);
 struct dentry *autofs_expire_indirect(struct super_block *sb,
 				      struct vfsmount *mnt,
 				      struct autofs_sb_info *sbi, int how);

fs/autofs/expire.c

@@ -292,10 +292,10 @@ static struct dentry *autofs_check_leaves(struct vfsmount *mnt,
 }
 
 /* Check if we can expire a direct mount (possibly a tree) */
-struct dentry *autofs_expire_direct(struct super_block *sb,
-				    struct vfsmount *mnt,
-				    struct autofs_sb_info *sbi,
-				    int how)
+static struct dentry *autofs_expire_direct(struct super_block *sb,
+					   struct vfsmount *mnt,
+					   struct autofs_sb_info *sbi,
+					   int how)
 {
 	unsigned long timeout;
 	struct dentry *root = dget(sb->s_root);