busybox: add missing install dir

Add missing /usr/sbin install dir fixing :

install: cannot create regular file 'build_dir/target-x86_64_musl/busybox-1.30.1/.pkgdir/busybox/usr/sbin/ntpd-hotplug': No such file or directory

Signed-off-by: Hans Dedecker <[email protected]>

package/utils/busybox/Makefile

@@ -9,7 +9,7 @@ include $(TOPDIR)/rules.mk
 
 PKG_NAME:=busybox
 PKG_VERSION:=1.30.1
-PKG_RELEASE:=1
+PKG_RELEASE:=2
 PKG_FLAGS:=essential
 
 PKG_SOURCE:=$(PKG_NAME)-$(PKG_VERSION).tar.bz2
@@ -120,6 +120,7 @@ endef
 
 define Package/busybox/install
 	$(INSTALL_DIR) $(1)/etc/init.d
+	$(INSTALL_DIR) $(1)/usr/sbin
 	$(CP) $(PKG_INSTALL_DIR)/* $(1)/
 ifneq ($(CONFIG_BUSYBOX_$(BUSYBOX_SYM)_CROND),)
 	$(INSTALL_BIN) ./files/cron $(1)/etc/init.d/cron