LP #1614885: Spurious Valgrind error on main.udf

**Reported in Launchpad by Laurynas Biveinis last update 19-08-2016 12:22:31

On 5.5 trunk with Valgrind, intermittently:

worker[2] Valgrind report from /mnt/workspace/percona-server-5.5-valgrind/BUILD_TYPE/valgrind/Host/ubuntu-xenial-64bit/mysql-test/var/2/log/mysqld.1.err after tests:
main.udf
--------------------------------------------------------------------------
HEAP SUMMARY:
in use at exit: 30,646,381 bytes in 239 blocks
total heap usage: 75,484 allocs, 75,245 frees, 111,270,654 bytes allocated

32 bytes in 1 blocks are still reachable in loss record 5 of 146
at 0x4C2DB8F: malloc (in /usr/lib/valgrind/vgpreload_memcheck-amd64-linux.so)
by 0x4016790: _dl_close_worker.part.0 (dl-close.c:393)
by 0x4017029: _dl_close_worker (dl-close.c:125)
by 0x4017029: _dl_close (dl-close.c:822)
by 0x4010393: _dl_catch_error (dl-error.c:187)
by 0x6740FCE: dlerror_run (dl-libc.c:46)
by 0x6740FCE: __libc_dlclose (dl-libc.c:222)
by 0x6771F86: free_mem (in /lib/x86_64-linux-gnu/libc-2.23.so)
by 0x6771BAF: __libc_freeres (in /lib/x86_64-linux-gnu/libc-2.23.so)
by 0x4A2868C: _vgnU_freeres (in /usr/lib/valgrind/vgpreload_core-amd64-linux.so)
by 0x6637F9A: __run_exit_handlers (exit.c:97)
by 0x6638034: exit (exit.c:104)
by 0x50805D: mysqld_exit(int) (mysqld.cc:1509)
by 0x5127E5: mysqld_main(int, char**) (mysqld.cc:4956)
by 0x50526E: main (main.cc:25)

33 bytes in 1 blocks are still reachable in loss record 43 of 146
at 0x4C2DB8F: malloc (in /usr/lib/valgrind/vgpreload_memcheck-amd64-linux.so)
by 0x401CD89: strdup (strdup.c:42)
by 0x401860E: _dl_load_cache_lookup (dl-cache.c:311)
by 0x4008F98: _dl_map_object (dl-load.c:2342)
by 0x400D9D1: openaux (dl-deps.c:63)
by 0x4010393: _dl_catch_error (dl-error.c:187)
by 0x400E011: _dl_map_object_deps (dl-deps.c:254)
by 0x4015411: dl_open_worker (dl-open.c:280)
by 0x4010393: _dl_catch_error (dl-error.c:187)
by 0x4014BD8: _dl_open (dl-open.c:660)
by 0x6740DDC: do_dlopen (dl-libc.c:87)
by 0x4010393: _dl_catch_error (dl-error.c:187)
by 0x6740E93: dlerror_run (dl-libc.c:46)
by 0x6740E93: __libc_dlopen_mode (dl-libc.c:163)
by 0x67267BD: nss_load_library (nsswitch.c:358)
by 0x67274F3: __nss_lookup_function (nsswitch.c:466)
by 0x67274F3: __nss_next2 (nsswitch.c:242)
by 0x67170ED: gethostbyaddr_r@@GLIBC_2.2.5 (getXXbyYY_r.c:281)

LEAK SUMMARY:
definitely lost: 0 bytes in 0 blocks
indirectly lost: 0 bytes in 0 blocks
possibly lost: 0 bytes in 0 blocks
still reachable: 65 bytes in 2 blocks
suppressed: 30,646,316 bytes in 237 blocks