gcc-3.5 patches

[Andrew Morton <akpm@xxxxxxxx>]

Dave, let me unload a bunch of patches which fix compilation errors and
warnings with gcc-3.5.  Most or all of these are applicable to gcc-3.4 as
well.

The most common problem is using a typecasted expression as an lvalue. 
This is actually a fatal error in gcc-3.5.

The sctp fix is interesting - sctp.h is using attribute((packed)) on all
its structures and as far as I can tell, it never did anything.