libcorkscrew buildfix for gcc 4.8

clearly gcc 4.8 is smarter than 4.7, so ignore it

Change-Id: I67c4c5e7c8d47ae4f9dfbe5c8d46a385a58ad933
init: Do not build logo.c when initlogo is disabled

For now, logo.c was build even if TARGET_NO_INITLOGO was true.
Changing tty to KD_GRAPHICS is now done in init.c as it should be, when
the logo is not present.

Change-Id: Ifabd9aebc9c0ad8d6903e963dfac031a6dac32e1