s390/cpumf: Fix lpp detection

BugLink: http://bugs.launchpad.net/bugs/1555344



we have to check bit 40 of the facility list before issuing LPP
and not bit 48. Otherwise a guest running on a system with
"The decimal-floating-point zoned-conversion facility" and without
the "The set-program-parameters facility" might crash on an lpp
instruction.

Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Cc: stable@vger.kernel.org # v4.4+
Fixes: e22cf8ca ("s390/cpumf: rework program parameter setting to detect guest samples")
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
(cherry picked from commit 7a76aa95)
Signed-off-by: Stefan Bader <stefan.bader@canonical.com>
Signed-off-by: Seth Forshee <seth.forshee@canonical.com>
Signed-off-by: Tim Gardner <tim.gardner@canonical.com>