update module count for current FreeBSD

Author: vladak

intro.tex

@@ -2319,7 +2319,7 @@
 kernel parameter had to be changed or add a device driver. In modern
 implementations it is possible to set many kernel parameters dynamically using
 system utilities. Also, many Unix systems extend kernel services by using
-\emph{loadable kernel modules}. For example FreeBSD 5.4-RELEASE has 392 such
+\emph{loadable kernel modules}. For example FreeBSD 15-RELEASE has 469 such
 modules.
 \item There are two ways to handle peripheral devices:
 \emph{block devices} and \emph{character/raw devices}. Block devices (e.g.