Fix a typographical error.

Change-Id: I94d226d246045141cb71b40d1f7520e35d2fbbf7
Reviewed-on: https://code-review.googlesource.com/14273
Reviewed-by: Paul Wankadia <junyer@google.com>
diff --git a/util/pcre.cc b/util/pcre.cc
index 883efb0..7e1d1ac 100644
--- a/util/pcre.cc
+++ b/util/pcre.cc
@@ -638,8 +638,8 @@
 
     // Avoid invoking undefined behavior when text.data() happens
     // to be null and start happens to be -1, the latter being the
-    // case for for an unmatched subexpression. Even if text.data()
-    // is not null, pointing one byte before was a longstanding bug.
+    // case for an unmatched subexpression. Even if text.data() is
+    // not null, pointing one byte before was a longstanding bug.
     const char* addr = NULL;
     if (start != -1) {
       addr = text.data() + start;