CID#1078500: Copy-paste error

Change-Id: Ibf553adbfe0b892d920e22d3a74d3433b6d6659a
Reviewed-on: https://gerrit.libreoffice.org/5853Reviewed-by: Markus Mohrhard <markus.mohrhard@googlemail.com>
Tested-by: Markus Mohrhard <markus.mohrhard@googlemail.com>

chart2/source/controller/dialogs/res_Trendline.cxx

@@ -130,7 +130,7 @@ void TrendlineResources::Reset( const SfxItemSet& rInAttrs )
     }
     else
     {
-        m_aNF_Period.SetValue( 2 );
+        m_aNF_Degree.SetValue( 2 );
     }
 
     if( rInAttrs.GetItemState( SCHATTR_REGRESSION_PERIOD, sal_True, &pPoolItem ) == SFX_ITEM_SET )