FileSaver: Do not rollback if we never opened the file

This will silence some warnings about removing files with empty
filenames which we get due to trying to remove a file we never
managed to open.

Calling finalize() unconditionally is the right thing to do here
as that processes and/or displays on error message to the user
if there is any.

Change-Id: Ibe7d07233f2c2698e53a7ad21041bc5cc4fcac0e
Reviewed-by: Oswald Buddenhagen <oswald.buddenhagen@digia.com>

src/libs/utils/fileutils.cpp

@@ -373,10 +373,12 @@ bool FileSaver::finalize()
         return FileSaverBase::finalize();
 
     SaveFile *sf = static_cast<SaveFile *>(m_file);
-    if (m_hasError)
-        sf->rollback();
-    else
+    if (m_hasError) {
+        if (sf->isOpen())
+            sf->rollback();
+    } else {
         setResult(sf->commit());
+    }
     delete sf;
     m_file = 0;
     return !m_hasError;