cam: Also reduce timeout for wlun probing

wlun probing was added after my initial work on this and was overlooked
in merging forward. Add the timeout here too, for the same reasons as
for REPORT LUNS. This doesn't change the default.

Fixes: 8ac7a3801c6a cam: Reduce overly long timeout values for initial device probing
Sponsored by: Netflix
Reviewed by: jaeyoon
Differential Revision: https://reviews.freebsd.org/D54184