[PATCH] uml: eliminate doubled boot output

CON_PRINTBUFFER was a bad idea for the mconsole console.  It causes the boot
output to be printed twice.

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