moused,syscons: Avoid warning if system has no /dev/ttyv*

A VM had no virtual terminals and emitted a warning on boot
`eval: cannot open /dev/ttyv*: No such file or directory`.

Break the loop in this case to avoid the warning.

PR:		289173
Reviewed by:	jlduran
Sponsored by:	The FreeBSD Foundation
Differential Revision: https://reviews.freebsd.org/D52344

libexec/rc/rc.d/moused

@@ -70,6 +70,7 @@ moused_start()
 	esac
 
 	for ttyv in /dev/ttyv* ; do
+		[ "$ttyv" = '/dev/ttyv*' ] && break
 		vidcontrol < ${ttyv} ${mousechar_arg} -m on
 	done
 }

libexec/rc/rc.d/syscons

@@ -238,6 +238,7 @@ syscons_configure_keyboard()
 		sc_init
 		echo -n ' allscreens_kbd'
 		for ttyv in /dev/ttyv*; do
+			[ "$ttyv" = '/dev/ttyv*' ] && break
 			kbdcontrol ${allscreens_kbdflags} < ${ttyv} > ${ttyv} 2>&1
 		done
 	fi
@@ -382,6 +383,7 @@ syscons_start()
 		sc_init
 		echo -n ' allscreens'
 		for ttyv in /dev/ttyv*; do
+			[ "$ttyv" = '/dev/ttyv*' ] && break
 			vidcontrol ${allscreens_flags} < ${ttyv} > ${ttyv} 2>&1
 		done
 	fi