zram: free secondary algorithms names

We need to kfree() secondary algorithms names when reset zram device that
had multi-streams, otherwise we leak memory.

[senozhatsky@chromium.org: kfree(NULL) is legal]
  Link: https://lkml.kernel.org/r/20240917013021.868769-1-senozhatsky@chromium.org
Link: https://lkml.kernel.org/r/20240911025600.3681789-1-senozhatsky@chromium.org


Fixes: 001d9273 ("zram: add recompression algorithm sysfs knob")
Signed-off-by: Sergey Senozhatsky <senozhatsky@chromium.org>
Cc: Minchan Kim <minchan@kernel.org>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>