Merge pull request #6 from cjdoucette/u4id

U4ID socket creation/checksumming updates
xia/xdp: allow non-XDP sinks on destination addresses

This is needed to support destination addresses with
not-XDP sinks that routing redirect to a local XDP XIDs.
xia/u4id: allow a remote U4ID XID to be a sink

It doesn't make sense to send packets to an XIP address in which
the final sink is a remote U4ID XID because no transport is expect
to deal with these packets at the destination.
Nevertheless, if the sink condition comes from a routing redirect,
it is fine since that the U4ID is just scoping the sink in this case.
xia: style fixes for indentation around parentheses

This patch complies with patch:
  - 91cb5195ff224dd9044cf927f80d9c633cdcffec
    checkpatch: expand parenthesis alignment test to declarations, ...

Fixed indentation issues raised by scripts/checkpatch.pl. Ignored
warnings when the indentation would have resulted in hard-to-read
code, such as for long parameter lists, long function names,
code that is heavily nested (and therefore close to the 80 column
mark), etc.
xia: style fixes for comments throughout code

This patch complies with patches:
  - 058806007450489bb8f457b275e5cb5c946320c1
    checkpatch: check networking specific block comment style
  - a605e32ebde25dc31f943fecb30e3e28079ccd06
    checkpatch: warn when networking block comment lines don't start with *

Fixed block commenting issues raised by scripts/checkpatch.pl. Ignored
warnings when an empty /* line is appropriate for defining a section
of code in a file, or when used for commenting out large chunks of
code.

Also fixed some comment spacing, punctuation, and spelling.
xia: style fixes for variable declarations

This patch complies with patch:
  - 3b617e3b80548096eda92ebd8382f76b139e011c
    checkpatch: net and drivers/net: warn on missing blank line after ...

Changed variable declarations so that there is a blank line separating
them with other code. Ignored the warning for better readability when
blocks of code (excluding declarations) was only one line.
xia: style fixes for curly braces

This patch complies with patch:
  - aad4f61498314d41d047ea2161b7bd7237b72d33
    checkpatch: add --strict tests for braces, comments and casts
xia: style fixes for space around casts

This patch complies with patch:
  - aad4f61498314d41d047ea2161b7bd7237b72d33
    checkpatch: add --strict tests for braces, comments and casts

Ignored warnings that are false positives using the sizeof operator.
xia: style fixes for whitespace
xia: style fixes for spaces after curly braces

This patch complies with patch:
  - 0979ae66464bd9793c6701861bccb21f9f118a52
    checkpatch: Add --strict messages for blank lines around braces
xia: style fixes for spaces around operators

This patch complies with patch:
  - 847316231c2f89918a2872e3d5fa3f5de11c39b6
    checkpatch: report missing spaces around trigraphs with --strict