Merge branch 'overlayfs-next' of git://git.kernel.org/pub/scm/linux/kernel/git/mszere...

Pull overlayfs fixes from Miklos Szeredi:
 "This fixes minor issues with the multi-layer update in v4.0"

* 'overlayfs-next' of git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/vfs:
  ovl: upper fs should not be R/O
  ovl: check lowerdir amount for non-upper mount
  ovl: print error message for invalid mount options