Clarify a comment.



git-svn-id: svn://svn.valgrind.org/valgrind/trunk@10641 a5019735-40e9-0310-863c-91ae7b9d1cf9
diff --git a/include/pub_tool_tooliface.h b/include/pub_tool_tooliface.h
index 1a36f15..19f2c4c 100644
--- a/include/pub_tool_tooliface.h
+++ b/include/pub_tool_tooliface.h
@@ -276,9 +276,10 @@
 
 /* Want to report errors from tool?  This implies use of suppressions, too. */
 extern void VG_(needs_tool_errors) (
-   // Identify if two errors are equal, or equal enough.  `res' indicates how
-   // close is "close enough".  `res' should be passed on as necessary, eg. if
-   // the Error's `extra' part contains an ExeContext, `res' should be
+   // Identify if two errors are equal, or close enough.  This function is
+   // only called if e1 and e2 will have the same error kind.  `res' indicates
+   // how close is "close enough".  `res' should be passed on as necessary,
+   // eg. if the Error's `extra' part contains an ExeContext, `res' should be
    // passed to VG_(eq_ExeContext)() if the ExeContexts are considered.  Other
    // than that, probably don't worry about it unless you have lots of very
    // similar errors occurring.