sys-apps/irqbalance: fix patch application

Note that the Meson build system was moved into the top-level in git
so this ugliness won't be needed in future.

Closes: https://bugs.gentoo.org/931190
Fixes: 42c7cfb893
Signed-off-by: Sam James <sam@gentoo.org>

sys-apps/irqbalance/irqbalance-1.9.4-r2.ebuild

@@ -33,10 +33,6 @@ RDEPEND="
 	selinux? ( sec-policy/selinux-irqbalance )
 "
 
-PATCHES=(
-	"${FILESDIR}"/${P}-drop-protectkerneltunables.patch
-)
-
 pkg_setup() {
 	CONFIG_CHECK="~PCI_MSI"
 	linux-info_pkg_setup
@@ -45,6 +41,11 @@ pkg_setup() {
 src_prepare() {
 	default
 
+	(
+		cd "${WORKDIR}"/${P} || die
+		eapply "${FILESDIR}"/${P}-drop-protectkerneltunables.patch
+	)
+
 	# Follow systemd policies
 	# https://wiki.gentoo.org/wiki/Project:Systemd/Ebuild_policy
 	sed \