vfs cache: Drop known argument of internal cache_recalc_neg_min()

'ncnegminpct' is to be passed always, so just drop the unneeded parameter.

Sponsored by: The FreeBSD Foundation
Reviewed by: mjg

Differential Revision: https://reviews.freebsd.org/D41763

(cherry picked from commit 02ef039c284b8a7b1ea40f5f9a851a3cb6af5b31)
(cherry picked from commit fc424de7e192bb33793ba1f7ed0c75b961809bf4)

Approved by: re (gjb)