memory: as_update_topology_pass: Improve comments

These comments were a little difficult to read. First one had
incorrect parenthesis. The part about attributes changing is
really applicable to the region being 'in both' rather than 'in
new'

Second comment has an obscure parenthetic about 'Logging may have
changed'. Made clearer, as this if is supposed to handle the case where
the memory region is unchanged (with the notable exception re logging).
Signed-off-by: NPeter Crosthwaite <peter.crosthwaite@xilinx.com>
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>

memory.c

@@ -719,7 +719,7 @@ static void address_space_update_topology_pass(AddressSpace *as,
                 || int128_lt(frold->addr.start, frnew->addr.start)
                 || (int128_eq(frold->addr.start, frnew->addr.start)
                     && !flatrange_equal(frold, frnew)))) {
-            /* In old, but (not in new, or in new but attributes changed). */
+            /* In old but not in new, or in both but attributes changed. */
 
             if (!adding) {
                 MEMORY_LISTENER_UPDATE_REGION(frold, as, Reverse, region_del);
@@ -727,7 +727,7 @@ static void address_space_update_topology_pass(AddressSpace *as,
 
             ++iold;
         } else if (frold && frnew && flatrange_equal(frold, frnew)) {
-            /* In both (logging may have changed) */
+            /* In both and unchanged (except logging may have changed) */
 
             if (adding) {
                 MEMORY_LISTENER_UPDATE_REGION(frnew, as, Forward, region_nop);