-Fix problem where copycds interrupted would not unmount images

git-svn-id: https://svn.code.sf.net/p/xcat/code/xcat-core/trunk@2011 8638fb3e-16cb-4fca-ae20-7b5d299a9bcd

xCAT-server/lib/xcat/plugins/anaconda.pm

@@ -805,6 +805,7 @@ sub copycd
             kill 2, $_;
         }
         if ($::CDMOUNTPATH) {
+            chdir("/");
             system("umount $::CDMOUNTPATH");
         }
     };

xCAT-server/lib/xcat/plugins/sles.pm

@@ -625,6 +625,7 @@ sub copycd
           kill 2, $_; 
        }
        if ($::CDMOUNTPATH) {
+            chdir("/");
             system("umount $::CDMOUNTPATH");
        }
     };

xCAT-server/lib/xcat/plugins/windows.pm

@@ -301,6 +301,7 @@ sub copycd
           kill 2, $_; 
        }
        if ($::CDMOUNTPATH) {
+            chdir("/");
             system("umount $::CDMOUNTPATH");
        }
     };