Unify GREEDY_REALLOC and GREEDY_REALLOC_T

greedy_realloc() and greedy_realloc0() now store the allocated
size as the count, not bytes.

Replace GREEDY_REALLOC uses with GREEDY_REALLOC_T everywhere,
and then rename GREEDY_REALLOC_T to GREEDY_REALLOC. It is just
too error-prone to have two slightly different macros which do the
same thing.

src/systemctl/systemctl.c

@@ -515,7 +515,7 @@ static int get_unit_list(
 
         _cleanup_bus_error_free_ sd_bus_error error = SD_BUS_ERROR_NULL;
         _cleanup_bus_message_unref_ sd_bus_message *reply = NULL;
-        size_t size;
+        size_t size = c;
         int r;
         UnitInfo u;
 
@@ -523,8 +523,6 @@ static int get_unit_list(
         assert(unit_infos);
         assert(_reply);
 
-        size = sizeof(UnitInfo) * c;
-
         r = sd_bus_call_method(
                         bus,
                         "org.freedesktop.systemd1",