Memory not freed upon reinstalling server_audit plugin

install soname 'server_audit';

uninstall soname 'server_audit';

install soname 'server_audit';

Warning: Memory not freed: 1688

Warning: 1688 bytes lost at 0x61c00002d8f0, allocated by T@0 at mysys/my_malloc.c:101, mysys/my_malloc.c:241, sql/sql_plugin.cc:3881, sql/sql_plugin.cc:4025, sql/sql_plugin.cc:1404, sql/sql_plugin.cc:2084, sql/sql_plugin.cc:2190, sql/sql_parse.cc:5927

Warning: 1688 bytes lost at 0x61c00002d8f0, allocated by T@0 at mysys/my_malloc.c:101, mysys/my_malloc.c:241, sql/sql_plugin.cc:3881, sql/sql_plugin.cc:4025, sql/sql_plugin.cc:1404, sql/sql_plugin.cc:2084, sql/sql_plugin.cc:2190, sql/sql_parse.cc:5927

Warning: Memory not freed: 1696

==2934130== 1,696 bytes in 1 blocks are definitely lost in loss record 1 of 1

==2934130==    at 0x483B7F3: malloc (in /usr/lib/x86_64-linux-gnu/valgrind/vgpreload_memcheck-amd64-linux.so)

==2934130==    by 0x1138126: my_malloc (my_malloc.c:101)

==2934130==    by 0x1138825: my_strdup (my_malloc.c:241)

==2934130==    by 0x721753: construct_options(st_mem_root*, st_plugin_int*, my_option*) (sql_plugin.cc:3881)

==2934130==    by 0x721DFE: test_plugin_options(st_mem_root*, st_plugin_int*, int*, char**) (sql_plugin.cc:4025)

==2934130==    by 0x71A197: plugin_initialize(st_mem_root*, st_plugin_int*, int*, char**, bool) (sql_plugin.cc:1404)

==2934130==    by 0x71C1D3: finalize_install(THD*, TABLE*, st_mysql_lex_string const*, int*, char**) (sql_plugin.cc:2084)

==2934130==    by 0x71C7F2: mysql_install_plugin(THD*, st_mysql_lex_string const*, st_mysql_lex_string const*) (sql_plugin.cc:2190)

==2934130==    by 0x709D61: mysql_execute_command(THD*) (sql_parse.cc:5927)

==2934130==    by 0x70F1A1: mysql_parse(THD*, char*, unsigned int, Parser_state*, bool, bool) (sql_parse.cc:7793)

==2934130==    by 0x6FD3FC: dispatch_command(enum_server_command, THD*, char*, unsigned int, bool, bool) (sql_parse.cc:1827)

==2934130==    by 0x6FBEF7: do_command(THD*) (sql_parse.cc:1381)

==2934130==    by 0x85CE44: do_handle_one_connection(CONNECT*) (sql_connect.cc:1336)

==2934130==    by 0x85CBA9: handle_one_connection (sql_connect.cc:1241)

==2934130==    by 0x10D80F3: pfs_spawn_thread (pfs.cc:1869)

==2934130==    by 0x4DBF608: start_thread (pthread_create.c:477)