x11-plugins/wmMatrix: use real usleep()

Closes: https://bugs.gentoo.org/898924
Signed-off-by: Bernard Cafarelli <voyageur@gentoo.org>

x11-plugins/wmMatrix/wmMatrix-0.2-r2.ebuild

@@ -1,4 +1,4 @@
-# Copyright 1999-2020 Gentoo Authors
+# Copyright 1999-2023 Gentoo Authors
 # Distributed under the terms of the GNU General Public License v2
 
 EAPI=7
@@ -27,6 +27,12 @@ PATCHES=(
 	"${FILESDIR}"/${P}-fno-common.patch
 	)
 
+src_prepare() {
+	default
+	# Use real usleep on modern systems
+	sed -e "s/short_uusleep/usleep/" -i wmMatrix.c || die
+}
+
 src_compile() {
 	# this version is distributed with compiled binaries!
 	make clean