SimilarityIndex: Correct comment explaining the logic

This comment was wrong, due to a copy-and-paste error.  Here the
code is looking at records of dst that do not exist in src, and
are skipping past them to find another match.

Change-Id: I07c1fba7dee093a1eeffcf7e0c7ec85446777ffb
Signed-off-by: Shawn O. Pearce <spearce@spearce.org>

org.eclipse.jgit/src/org/eclipse/jgit/diff/SimilarityIndex.java

@@ -230,8 +230,8 @@ class SimilarityIndex {
 					break;
 				srcKey = keyOf(srcHash[srcIdx]);
 
-			} else /* if (srcKey > dstKey) */{
-				// Regions of dst which do not appear in dst.
+			} else /* if (dstKey < srcKey) */{
+				// Regions of dst which do not appear in src.
 				if (++dstIdx == dstHash.length)
 					break;
 				dstKey = keyOf(dstHash[dstIdx]);