kconfig: improve config load/save output

During loading special case the first common case (.config), be silent about
it and otherwise mark it as a change that requires saving.  Instead output
that the file has been changed.  IOW if conf does nothing (special), it's
silent.

Signed-off-by: Roman Zippel <zippel@linux-m68k.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Sam Ravnborg <sam@ravnborg.org>