Fix uninitialized variable use bug found by the clairvoyant static analyzer.

Commit::canReplaceText would not initialize its out 'Len' parameter before
returning true and it would be used uninitialized in Commit::replaceText.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@159306 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Edit/Commit.cpp b/lib/Edit/Commit.cpp
index c45ee1f..41c72e4 100644
--- a/lib/Edit/Commit.cpp
+++ b/lib/Edit/Commit.cpp
@@ -332,6 +332,7 @@
   if (invalidTemp)
     return false;
 
+  Len = text.size();
   return file.substr(Offs.getOffset()).startswith(text);
 }