[4.4] Follow up fixes for 3fe6e52f0626 ("ovl: override creds with the ones from the superblock mounter")

Upstream commit 3fe6e52f0626 ("ovl: override creds with the ones from the superblock mounter") is present in v4.4.156 as 121b09d30d48. But the patch has a few follow up fixes in upstream that also have to be applied to 4.4: d0e13f5bbe4b ("ovl: fix uid/gid when creating over whiteout") in v4.7-rc4 8fc646b44385 ("ovl: fix random return value on mount") in v4.13-rc2

The first patch should fix v4.4.156 regression reported here: https://bugzilla.kernel.org/show_bug.cgi?id=201633.

Rest of stable kernels (4.9+) already have these followup fixes.