uml: style fixes in arch/um/sys-x86_64

Style fixes in arch/um/sys-x86_64:
	updated copyrights
	CodingStyle fixes
	added severities to printks which needed them

A bunch of functions in sys-*/ptrace_user.c turn out to be unused, so they and
their declarations are gone.

Signed-off-by: Jeff Dike <jdike@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>