test/system: fix test race in exec leak check

On very slow systems it can be that it takes over 5s after the sleep
process was started and until the find_exec_pid_files function finds the
file. This was observed on a ppc64le machine by Red Hat QE.

Just making the sleep longer should fix that problem and it doesn't
really effect the total test time because we stop the container
afterwards so there is no extra delay added with this either.

Signed-off-by: Paul Holzinger <pholzing@redhat.com>

Author: Luap99

test/system/075-exec.bats

@@ -64,7 +64,7 @@ load helpers
     is "$(find_exec_pid_files)" "" "there isn't any exec pid hash file leak"
 
     # Ensure file is there while container is running
-    run_podman exec -d $cid sleep 5
+    run_podman exec -d $cid sleep 100
     is "$(find_exec_pid_files)" '.*containers.*exec_pid' "exec_pid file found"
 
     run_podman rm -t 0 -f $cid