[supervisord]: use abspath as supervisord entrypoint (#5995)

use abspath makes the entrypoint not affected by PATH env.

Signed-off-by: Guohan Lu <lguohan@gmail.com>

dockers/docker-database/docker-database-init.sh

@@ -55,7 +55,7 @@ if [[ $DATABASE_TYPE == "chassisdb" ]]; then
     # generate all redis server supervisord configuration file
     sonic-cfggen -j $db_cfg_file_tmp -t /usr/share/sonic/templates/supervisord.conf.j2 > /etc/supervisor/conf.d/supervisord.conf
     rm $db_cfg_file_tmp
-    exec supervisord
+    exec /usr/local/bin/supervisord
     exit 0
 fi
 
@@ -79,4 +79,4 @@ else
 fi
 rm $db_cfg_file_tmp
 
-exec supervisord
+exec /usr/local/bin/supervisord