errl: Mark errlogMsgHandler() as detached

This ensures we crash if we can't process error log messages properly.
Currently the boot will just hang without any obvious reason if the task
crashes.

Change-Id: I939f720b04274ec6718690b7126db7103f9f1003
Signed-off-by: Andrew Jeffery <andrewrj@au1.ibm.com>
Reviewed-on: http://rchgit01.rchland.ibm.com/gerrit1/67274
Tested-by: Jenkins Server <pfd-jenkins+hostboot@us.ibm.com>
Tested-by: Jenkins OP Build CI <op-jenkins+hostboot@us.ibm.com>
Tested-by: Jenkins OP HW <op-hw-jenkins+hostboot@us.ibm.com>
Tested-by: FSP CI Jenkins <fsp-CI-jenkins+hostboot@us.ibm.com>
Reviewed-by: Daniel M. Crowell <dcrowell@us.ibm.com>

src/usr/errl/errlmanager.C

@@ -263,6 +263,8 @@ void ErrlManager::errlogMsgHndlr ()
 {
     TRACFCOMP( g_trac_errl, ENTER_MRK "Enter ErrlManager::errlogMsgHndlr" );
 
+    task_detach();
+
     while( 1 )
     {
         msg_t * theMsg = msg_wait( iv_msgQ );