aufs: bugfix, handling an error in opening a FIFO

When an error happens in opening a FIFO, aufs forgot freeing a file
object. The bad effect is the usage counter of a branch became
incorrect.

Signed-off-by: J. R. Okajima <hooanon05g@gmail.com>
Merge remote-tracking branch 'aufs3-standalone/aufs3.9/00base' into aufs3.9/10static
Merge branch 'aufs3.9/10static' into aufs3.9/11proc_map
Merge branch 'aufs3.9/11proc_map' into aufs3.9/18public
aufs mmap: bugfix remap_file_pages(2)

While the comment in mm/fremap.c says that remap_file_pages(2) does not
create any new vmas, I confirmed the cases doing that.
So we have to support both cases, a new vma is created and not created.

Signed-off-by: J. R. Okajima <hooanon05g@gmail.com>
Merge branch 'aufs3.9/11proc_map' into aufs3.9/18public