Reuse existing data buffer in contentprovider

A few lines up we already call `p.data(false)`.

Change-Id: I58035a7694fa9d36d679790e4cfdd25e72d8ba71
diff --git a/contentprovider.go b/contentprovider.go
index f6aa94d..62fd149 100644
--- a/contentprovider.go
+++ b/contentprovider.go
@@ -211,7 +211,7 @@
 			LineEnd:    lineEnd,
 			LineNumber: num,
 		}
-		finalMatch.Line = p.data(false)[lineStart:lineEnd]
+		finalMatch.Line = data[lineStart:lineEnd]
 
 		for _, m := range lineCands {
 			fragment := LineFragmentMatch{