include/linux/printk.h: use and neaten no_printk

- Move no_printk above first CONFIG_PRINTK block so it can be used by
  printk_once.

- Convert statement expression if (0) printk macros to no_printk.

- Convert printk_once(x...) to more normally used (fmt, ...) fmt,
  ##__VA_ARGS__.

- Standardize __attribute__ use.

- Expand single line inline functions.

- Remove space before pointer.

Signed-off-by: Joe Perches <joe@perches.com>
Cc: Matt Mackall <mpm@selenic.com>
Cc: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>