Find usage displays content of the first line

Task-number: QTCREATERBUG-6176

Change-Id: I1c45b951bfde0b0d33bf462f532da7cbdbaa3fe7
Reviewed-by: Leandro Melo <leandro.melo@nokia.com>

src/libs/cplusplus/FindUsages.cpp

@@ -50,17 +50,21 @@ QString fetchLine(const QByteArray &bytes, const int line)
 {
     int current = 0;
     const char *s = bytes.constData();
+
+    if (line) {
         while (*s) {
             if (*s == '\n') {
                 ++current;
-            if (current == line)
+                if (line == current) {
+                    ++s;
                     break;
                 }
+            }
             ++s;
         }
+    }
 
     if (current == line) {
-        ++s;
         const char *e = s;
         while (*e && *e != '\n')
             ++e;