xwayland/test: Don't catch errors in run-piglit.sh
The xwayland-piglit.sh script spawns weston, runs run-piglit.sh and finally kills weston.
However, this whole script is running with “-e” meaning that any error will cause the script to exit immediately.
As a result, if run-piglit.sh exits with a non-zero code such as 77 for skipping the test, the script will exit prematurely leaving weston running, and meson will simply wait until the timeout kicks in, and fail eventually instead of skipping the test as it should.
Fix this by removing the option to exit immediately prior to spawn the script run-piglit.sh.