Print preprocessor directives (usually "#ifdef CONFIG_SOMETHING" and "#endif")
in structs definitions correctly (-text, -html, sgmldocs, htmldocs, pdfdocs,
mandocs).

Correctly means:
 - on the separate line
 - starting from column 0
 - not glued to the type of the next member
 - not breeding if members are separated by comma
 - not imitating pointers to functions ("#if defined(CONFIG_X)...")
 - not giving bogus warnings because of this imitation
Signed-off-by: Alexey Dobriyan <adobriyan@mail.ru>
Signed-off-by: Sam Ravnborg <sam@ravnborg.org>