svtools: rename function to match it's effect.

nYoffsNodeBmp went with
commit 9e61a951
Date:   Tue Jun 20 15:59:42 2017 +0200
    loplugin:unusedfields in svtools

Change-Id: I959829c64242b2d021497f828e24bb23119d8e24
Reviewed-on: https://gerrit.libreoffice.org/41363Reviewed-by: Noel Grandin <noel.grandin@collabora.co.uk>
Tested-by: Jenkins <ci@libreoffice.org>
Reviewed-by: Jochen Nitschke <j.nitschke+logerrit@ok.de>

svtools/source/contnr/svimpbox.cxx

@@ -1457,8 +1457,8 @@ long SvImpLBox::GetEntryLine( SvTreeListEntry* pEntry ) const
 
 void SvImpLBox::SetEntryHeight()
 {
-    SetNodeBmpYOffset( GetExpandedNodeBmp() );
-    SetNodeBmpYOffset( GetCollapsedNodeBmp() );
+    SetNodeBmpWidth( GetExpandedNodeBmp() );
+    SetNodeBmpWidth( GetCollapsedNodeBmp() );
     if(!pView->HasViewData()) // are we within the Clear?
     {
         Size aSize = pView->Control::GetOutputSizePixel();
@@ -1565,7 +1565,7 @@ void SvImpLBox::CollapsingEntry( SvTreeListEntry* pEntry )
 }
 
 
-void SvImpLBox::SetNodeBmpYOffset( const Image& rBmp )
+void SvImpLBox::SetNodeBmpWidth( const Image& rBmp )
 {
     const Size aSize( rBmp.GetSizePixel() );
     nNodeBmpWidth = aSize.Width();

svtools/source/inc/svimpbox.hxx

@@ -161,7 +161,7 @@ private:
     DECL_LINK( ScrollLeftRightHdl, ScrollBar*, void );
     DECL_LINK( EndScrollHdl, ScrollBar*, void );
 
-    void                SetNodeBmpYOffset( const Image& );
+    void                SetNodeBmpWidth( const Image& );
     void                SetNodeBmpTabDistance();
 
     // Selection-Engine
@@ -346,13 +346,13 @@ inline Image& SvImpLBox::implGetImageLocation( const ImageType _eType )
 inline void SvImpLBox::SetExpandedNodeBmp( const Image& rImg )
 {
     implGetImageLocation( ImageType::NodeExpanded ) = rImg;
-    SetNodeBmpYOffset( rImg );
+    SetNodeBmpWidth( rImg );
 }
 
 inline void SvImpLBox::SetCollapsedNodeBmp( const Image& rImg )
 {
     implGetImageLocation( ImageType::NodeCollapsed ) = rImg;
-    SetNodeBmpYOffset( rImg );
+    SetNodeBmpWidth( rImg );
 }
 
 inline const Image& SvImpLBox::GetDontKnowNodeBmp( )