uml: remove now unused code

This patch finishes what the previous one started.  The code was not used
after my first patch, and now can be removed with ease.

[ jdike - also deleted the #if 0 lcall stuff ]

Signed-off-by: Karol Swietlicki <magotari@gmail.com>
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>