repart: show partitions we don't grow/create as "unchanged"

The previous string was "unknown", but that's wrong, because we *do*
know what we are going to do with those partitions: we leave them
unmodified, hence say "unchanged" in the output, to be clearer.

src/partition/repart.c

@@ -2037,7 +2037,7 @@ static int context_dump_partitions(Context *context, const char *node) {
                                 TABLE_UINT64, p->current_padding == UINT64_MAX ? 0 : p->current_padding,
                                 TABLE_UINT64, p->new_padding,
                                 TABLE_STRING, padding_change, TABLE_SET_COLOR, !p->partitions_next && sum_padding > 0 ? ansi_underline() : NULL,
-                                TABLE_STRING, activity ?: "unknown");
+                                TABLE_STRING, activity ?: "unchanged");
                 if (r < 0)
                         return table_log_add_error(r);
         }