libubox: implement ulog_close() and call it on ulog_open()

This is required to properly update syslog idents when switching between
log modes.

Signed-off-by: Jo-Philipp Wich <jow@openwrt.org>

SVN-Revision: 44546

package/libs/libubox/Makefile

@@ -1,13 +1,13 @@
 include $(TOPDIR)/rules.mk
 
 PKG_NAME:=libubox
-PKG_VERSION:=2015-02-26
+PKG_VERSION:=2015-02-26.1
 PKG_RELEASE=$(PKG_SOURCE_VERSION)
 
 PKG_SOURCE_PROTO:=git
 PKG_SOURCE_URL:=http://git.openwrt.org/project/libubox.git
 PKG_SOURCE_SUBDIR:=$(PKG_NAME)-$(PKG_VERSION)
-PKG_SOURCE_VERSION:=ca6d5472056ceee4b8ab320167e0ae8155a95985
+PKG_SOURCE_VERSION:=2a9edb464215d17c61fdaa6fbd97c99f1f130812
 PKG_SOURCE:=$(PKG_NAME)-$(PKG_VERSION)-$(PKG_SOURCE_VERSION).tar.gz
 PKG_MIRROR_MD5SUM:=
 CMAKE_INSTALL:=1