package/tini: install docker-init symlink

This removes the warning that docker can't find docker-init in PATH.

Signed-off-by: Christian Stewart <christian@paral.in>
Signed-off-by: Tian Yuanhao <tianyuanhao@aliyun.com>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@bootlin.com>
(cherry picked from commit 072af885c4afedf4f131563a755c532f8ad45650)
Signed-off-by: Peter Korsgaard <peter@korsgaard.com>

package/tini/tini.mk

@@ -30,6 +30,7 @@ endef
 
 define TINI_INSTALL_TARGET_CMDS
 	$(INSTALL) -D -m 0755 $(@D)/bin/tini $(TARGET_DIR)/usr/bin/tini
+	ln -sf tini $(TARGET_DIR)/usr/bin/docker-init
 endef
 
 # Tini's CMakeLists.txt is not suitable for Buildroot.