Fix copy-paste typo in CloneCommand#cleanup

deleteChildren was called on directory instead of gitDir, leading to a
potential null pointer exception if the git directory existed initially.

Bug: 550340
Change-Id: Iafc3b2961253a99862a59e81c7371f7bc564b412
Signed-off-by: Adrien Bustany <adrien-xx-eclipse@bustany.org>

org.eclipse.jgit/src/org/eclipse/jgit/api/CloneCommand.java

@@ -700,7 +700,7 @@ public class CloneCommand extends TransportCommand<CloneCommand, Git> {
 					FileUtils.delete(gitDir, FileUtils.RECURSIVE
 							| FileUtils.SKIP_MISSING | FileUtils.IGNORE_ERRORS);
 				} else {
-					deleteChildren(directory);
+					deleteChildren(gitDir);
 				}
 			}
 		} catch (IOException e) {