Update git submodules

Update git submodules

* Update swift from branch 'master'
  to 8bf6e090f4753f7e9d1df1ef2bea46aad9c6e088
  - Merge "test_diskfile.py: fix failing test if O_TMPFILE unsupported"
  - test_diskfile.py: fix failing test if O_TMPFILE unsupported

    Previously test_commit_overwritten_before_ppi_rename would fail when
    O_TMPFILE is not supported (e.g macos) because an extra, unexpected,
    rename call is made to rename a temporary file to a data file.

    Change-Id: I30f4dcee50e30e3c501b302e2242dc1abe9b6b62
    Signed-off-by: Alistair Coles <alistairncoles@gmail.com>