-Ensure that runcmd3 grabs all the output even if managed application pauses

git-svn-id: https://svn.code.sf.net/p/xcat/code/xcat-core/trunk@6165 8638fb3e-16cb-4fca-ae20-7b5d299a9bcd

perl-xCAT/xCAT/Utils.pm

@@ -905,7 +905,8 @@ sub runcmd3 { #a proper runcmd that indpendently returns stdout, stderr, pid and
     }
     close($cmdin);
     my @handles;
-    while (@handles = $cmdsel->can_read()) {
+    while ($cmdsel->count())) {
+        @handles = $cmdsel->can_read();
         foreach (@handles) {
             my $line;
             my $done = sysread $_,$line,180;