- remove spurious spaces and tabs at end of lines
  - make sure if, while, for, switch has a space before the opening '('
  - make sure no line has more than 80 chars
  - move initializations to the declaration line where possible
  - bitwise, logical and arithmetic operators have spaces before and after,
    improving readability of complex expressions
  - remove uneeded () in returns
  - use named member initializations in structs
  - other minor cleanups

Sizes:
Before:
   text    data     bss     dec     hex filename
  19408    2560       8   21976    55d8 net/ipv4/tcp_ipv4.o
After:
   text    data     bss     dec     hex filename
  19312    2560      12   21884    557c net/ipv4/tcp_ipv4.o