-Fix problem where nested eval assigned $@ could break commands (a la the ip6 support)

git-svn-id: https://svn.code.sf.net/p/xcat/code/xcat-core/trunk@6292 8638fb3e-16cb-4fca-ae20-7b5d299a9bcd

xCAT-server/sbin/xcatd

@@ -938,6 +938,7 @@ sub plugin_command {
           close($parent_fd);
           xexit(0);
         } 
+        $@=""; #sometimes a child 'eval' doesn't clean up $@, if we make it this far, no non-eval bug bombed out
         }; #REMOVEEVALFORDEBUG
         if ($sock or $shouldbealivepid != $$) { #We shouldn't still be alive, try to send as much detail to parent as possible as to why
             my $error= "$modname plugin bug, pid $$, process description: '$$progname'";