KVM: PPC: Book3S HV: XIVE: Fix potential page leak on error path

KVM: PPC: Book3S HV: XIVE: Fix potential page leak on error path

commit 30486e72093ea2e594f44876b7a445c219449bce upstream.

We need to check the host page size is big enough to accomodate the
EQ. Let's do this before taking a reference on the EQ page to avoid
a potential leak if the check fails.

Cc: stable@vger.kernel.org # v5.2
Fixes: 13ce3297c576 ("KVM: PPC: Book3S HV: XIVE: Add controls for the EQ configuration")
Signed-off-by: Greg Kurz <groug@kaod.org>
Reviewed-by: Cédric Le Goater <clg@kaod.org>
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>