selftests/x86/vm86: Fix entry_from_vm86 test on 64-bit kernels

selftests/x86/vm86: Fix entry_from_vm86 test on 64-bit kernels

The test failed due to an oversight on my part when run on a
64-bit kernel.  vm86 isn't expected to work at all, and I
mistakenly failed one part of the test because no signal was
delivered.

Signed-off-by: Andy Lutomirski <luto@kernel.org>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Shuah Khan <shuahkh@osg.samsung.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/502c8bef877b33fe4943885ded6125dfcc7892db.1438205722.git.luto@kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>