[PATCH] i386: Don't let ptrace set the nested task bit

There's no good reason for allowing ptrace to set the NT bit in EFLAGS, so
mask it off.

Signed-off-by: Chuck Ebbert <76306.1226@compuserve.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>