sd-bus: correct size calculation in DBus fd receive

The size of the allocated array for received file descriptors was
incorrectly calculated. This did not matter when a single file
descriptor was received, but for more descriptors the allocation was
insufficient.

src/libsystemd/sd-bus/bus-socket.c

@@ -985,7 +985,7 @@ int bus_socket_read_message(sd_bus *bus) {
                                         return -EIO;
                                 }
 
-                                f = realloc(bus->fds, sizeof(int) + (bus->n_fds + n));
+                                f = realloc(bus->fds, sizeof(int) * (bus->n_fds + n));
                                 if (!f) {
                                         close_many((int*) CMSG_DATA(cmsg), n);
                                         return -ENOMEM;