autofs4: fix invalid ioctl return in autofs4_root_ioctl_unlocked()

The return from an ioctl if an invalid ioctl is passed in should be
EINVAL not ENOSYS.

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/autofs4/root.c

@@ -914,7 +914,7 @@ static int autofs4_root_ioctl_unlocked(struct inode *inode, struct file *filp,
 					    filp->f_path.mnt, sbi, p);
 
 	default:
-		return -ENOSYS;
+		return -EINVAL;
 	}
 }