[PATCH i-g-t 2/3] lib/eudebug: Fix xe_eudebug_client_stop corner case

["Dominik Karol Piątkowski" <dominik.karol.piatkowski@intel.com>]

After `token_signal(c->p_in, CLIENT_STOP, c->pid)`, the client is
expected to end its work and exit. By the time the waitpid() is called,
the client process may be gone already, resulting in a failed assert.

Fix it by skipping the assert in case of errno being ECHILD, meaning
the process already exited.

Signed-off-by: Dominik Karol Piątkowski <dominik.karol.piatkowski@intel.com>
---
 lib/xe/xe_eudebug.c | 8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)

diff --git a/lib/xe/xe_eudebug.c b/lib/xe/xe_eudebug.c
index ad8bdf68a..58acb1dea 100644
--- a/lib/xe/xe_eudebug.c
+++ b/lib/xe/xe_eudebug.c
@@ -1450,12 +1450,16 @@ void xe_eudebug_client_stop(struct xe_eudebug_client *c)
 {
 	if (c->pid) {
 		int waitstatus;
+		int ret;
 
 		xe_eudebug_client_wait_done(c);
 
 		token_signal(c->p_in, CLIENT_STOP, c->pid);
-		igt_assert_eq(waitpid(c->pid, &waitstatus, 0),
-			      c->pid);
+		ret = waitpid(c->pid, &waitstatus, 0);
+		/* process may be gone already */
+		if (!(ret == -1 && errno == ECHILD))
+			igt_assert_eq(ret, c->pid);
+
 		c->pid = 0;
 	}
 }
-- 
2.34.1