[RFC trivial] printk.c: /proc/vmcore instead of /proc/vmcoreinfo in comments?

[Dirk Gouders]

 Hello Joe,

when having a look at printk.c, I noticed that two comments refer
to /proc/vmcoreinfo and I wonder if that should not read /proc/vmcore.

While at it, a typo in one of those coments could also be fixed.

Best regards,

Dirk