init-functions: Add two functions

Add log_begin_msg() and log_end_msg () in init-functions because some startup scripts need them.
if there are not two functions, then error information will arise on screen.
for example,
$ /etc/init.d/avahi-daemon start
/etc/init.d/avahi-daemon: line 161: log_begin_msg: command not found
/etc/init.d/avahi-daemon: line 163: log_end_msg: command not found

[YOCTO #1907]

(From OE-Core rev: 05682408ef7fca6029e48a18b2f660eeec65a4ec)

Signed-off-by: Xiaofeng Yan <xiaofeng.yan@windriver.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

meta/recipes-extended/lsb/lsb/init-functions

@@ -30,3 +30,10 @@ log_warning_msg () {
 	/etc/core-lsb/lsb_log_message warning "$@"
 }
 
+log_begin_msg () {
+	/etc/core-lsb/lsb_log_message begin "$@"
+}
+
+log_end_msg () {
+	/etc/core-lsb/lsb_log_message end "$@"
+}