s390x: remove double compat statement

We chain our compat handler via the CCW_COMPAT macros and via the
class_init function. (e.g. ccw_machine_2_7_class_options calls
ccw_machine_2_8_class_options). As all class_init functions in that
chain call SET_MACHINE_COMPAT for their compat settings, and
SET_MACHINE_COMPAT will append there is no need to do that again.
Signed-off-by: NChristian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: NCornelia Huck <cornelia.huck@de.ibm.com>

hw/s390x/s390-virtio-ccw.c

@@ -339,7 +339,6 @@ static const TypeInfo ccw_machine_info = {
         HW_COMPAT_2_7
 
 #define CCW_COMPAT_2_6 \
-        CCW_COMPAT_2_7 \
         HW_COMPAT_2_6 \
         {\
             .driver   = TYPE_S390_IPL,\
@@ -352,7 +351,6 @@ static const TypeInfo ccw_machine_info = {
         },
 
 #define CCW_COMPAT_2_5 \
-        CCW_COMPAT_2_6 \
         HW_COMPAT_2_5
 
 #define CCW_COMPAT_2_4 \