Memleak found by ASAN:
Direct leak of 21 byte(s) in 1 object(s) allocated from:
#0 0x7fe7a917fe8f in malloc (/usr/lib/x86_64-linux-gnu/libasan.so.6+0xa9e8f)
#1 0x7fe7a9129874 (/usr/lib/x86_64-linux-gnu/libasan.so.6+0x53874)
#2 0x7fe7a5a23469 in weston_wm_window_read_properties ../xwayland/window-manager.c:574
#3 0x7fe7a5a28d3b in weston_wm_handle_map_request ../xwayland/window-manager.c:1178
#4 0x7fe7a5a31660 in weston_wm_handle_event ../xwayland/window-manager.c:2291
#5 0x7fe7a8c261a1 in wl_event_loop_dispatch ../src/event-loop.c:1027
Signed-off-by: Marius Vlad <marius.vlad@collabora.com>