Fixes ASan reported leak:
Direct leak of 136 byte(s) in 1 object(s) allocated from:
#0 0x7ff60173c518 in calloc (/lib/x86_64-linux-gnu/libasan.so.5+0xe9518)
#1 0x7ff5fcfed3fa in zalloc ../../git/weston/include/libweston/zalloc.h:38
#2 0x7ff5fcfed8bf in wet_module_init ../../git/weston/tests/ivi-layout-test-plugin.c:196
#3 0x7ff60161bd81 in wet_load_module ../../git/weston/compositor/main.c:941
#4 0x7ff60161c165 in load_modules ../../git/weston/compositor/main.c:1012
#5 0x7ff60162ced9 in wet_main ../../git/weston/compositor/main.c:3441
#6 0x559a98fd7d4c in execute_compositor ../../git/weston/tests/weston-test-fixture-compositor.c:432
#7 0x559a98fdb780 in weston_test_harness_execute_as_client ../../git/weston/tests/weston-test-runner.c:528
#8 0x559a98fcbc48 in fixture_setup ../../git/weston/tests/ivi-layout-test-client.c:48
#9 0x559a98fcbcca in fixture_setup_run_ ../../git/weston/tests/ivi-layout-test-client.c:50
#10 0x559a98fdbd35 in main ../../git/weston/tests/weston-test-runner.c:661
#11 0x7ff60129109a in __libc_start_main ../csu/libc-start.c:308
#12 0x559a98fcb769 in _start (/home/pq/build/weston-meson/tests/test-ivi-layout-client+0xd769)
This also plugs the leak on wl_global_create() error path, though it
cannot really be tested.
Signed-off-by: Pekka Paalanen <pekka.paalanen@collabora.com>