bail out for error cells early

Change-Id: I36581f3b735008dbba6eea5808da654eb8b279e3

sc/source/filter/excel/xestream.cxx

@@ -674,23 +674,23 @@ static const char* lcl_GetErrorString( sal_uInt16 nScErrCode )
 
 void XclXmlUtils::GetFormulaTypeAndValue( ScFormulaCell& rCell, const char*& rsType, OUString& rsValue )
 {
-    switch( rCell.GetFormatType() )
-    {
-        case NUMBERFORMAT_NUMBER:
-        {
-            // either value or error code
     sal_uInt16 nScErrCode = rCell.GetErrCode();
     if( nScErrCode )
     {
         rsType = "e";
         rsValue = ToOUString( lcl_GetErrorString( nScErrCode ) );
+
+        return;
     }
-            else
+
+    switch( rCell.GetFormatType() )
     {
+        case NUMBERFORMAT_NUMBER:
+        {
+            // either value or error code
             rsType = "n";
             rsValue = OUString::valueOf( rCell.GetValue() );
         }
-        }
         break;
 
         case NUMBERFORMAT_TEXT: