Revert "chase: invert CHASE_NO_AUTOFS and only set it where needed"

Revert "chase: invert CHASE_NO_AUTOFS and only set it where needed"

This reverts commit 490aa05ca1ba8e3e2a5ed13e1a77f5ea9f1c93b0.

As commented https://github.com/systemd/systemd/pull/38569#discussion_r2284978273,
the commit makes autofs check bypassed. Before the commit, when
CHASE_NO_AUTOFS is set, we did not shortcut chasing paths, and refused
any autofs mount points in the path. However, with the commit, the flag
was swapped but even when CHASE_AUTOFS is unset, the autofs check may be
skipped.

To fix the issue, rather than swapping the flag, we should introduce
another flag, say CHASE_TRIGGER_AUTOFS. This revert the commit, and in a
later commit, the new flag will be introduced.