Revert "net: rtnetlink: use BIT for flag values"

This reverts commit b3eed4bf which is
commit 0569e31f upstream.

It breaks the Android kernel abi and can be brought back in the future
in an abi-safe way if it is really needed.

Bug: 161946584
Change-Id: Idf0c4ae34007eabf54c7269dfb5bd6ec5aca6b9f
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>