[PATCH] uml: correct removal of pte_mkexec

Correct commit 5906e417 - this makes more
sense: we turn pte_mkexec + pte_wrprotect to pte_mkread.  However, due to a
bug in pte_mkread, it does the exact same thing as pte_mkwrite, so this patch
improves the code but does not change anything in practice.  The pte_mkread
bug is fixed separately, as it may have big impact.

Signed-off-by: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
Cc: Jeff Dike <jdike@addtoit.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>