Revert "inet: shrink struct flowi_common"

This reverts commit 612c22e9 which is
commit 1726483b upstream.

It only moves things around a structure, AND it saves lots of memory,
but in doing so breaks the stable Android ABI, so it must be reverted
(Android devices have plenty of kernel memory...)  If this is to come
back in the future, it can do so in an abi-safe way.

Bug: 161946584
Change-Id: I5a5a40c6f6982122d766f3fe5cfde3f3514bc9ae
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>