main: do not exit in case stdin is not a valid stream
Weston should not exit if stdin is not a valid stream. This allows to launch with a closed stdin:
weston <&-
This fixes screen sharing using weston: Weston closes the stdin before forking itself to execute the screen sharing instance of weston. Before this patch screen sharing failed with: Screen share failed: No wl_shm found unknown child process exited
Fixes: f0d39b22 ("weston: Set CLOEXEC on stdin") Signed-off-by: Stefan Agner stefan@agner.ch