Clean up a few unused names of caught exceptions

eeschema/libedit/lib_manager.cpp

@@ -649,7 +649,7 @@ bool LIB_MANAGER::addLibrary( const wxString& aFilePath, bool aCreate, SYMBOL_LI
         {
             aTable->CreateSymbolLib( libName );
         }
-        catch( const IO_ERROR& e )
+        catch( const IO_ERROR& )
         {
             aTable->RemoveRow( libRow );
             return false;
@@ -967,7 +967,7 @@ bool LIB_MANAGER::LIB_BUFFER::SaveBuffer( LIB_MANAGER::PART_BUFFER::PTR aPartBuf
         {
             cachedParent = aPlugin->LoadSymbol( m_libName, bufferedParent->GetName() );
         }
-        catch( const IO_ERROR& ioe )
+        catch( const IO_ERROR& )
         {
             return false;
         }

eeschema/tools/lib_edit_tool.cpp

@@ -659,7 +659,7 @@ int LIB_EDIT_TOOL::Paste( const TOOL_EVENT& aEvent )
         reader.ReadLine();
         newPart = SCH_LEGACY_PLUGIN::ParsePart( reader );
     }
-    catch( IO_ERROR& e )
+    catch( IO_ERROR& )
     {
         // If it's not a part then paste as text
         newPart = new LIB_PART( "dummy_part" );

eeschema/tools/sch_editor_control.cpp

@@ -977,7 +977,7 @@ int SCH_EDITOR_CONTROL::Paste( const TOOL_EVENT& aEvent )
     {
         plugin.LoadContent( reader, &paste_screen );
     }
-    catch( IO_ERROR& e )
+    catch( IO_ERROR& )
     {
         // If it wasn't content, then paste as text
         paste_screen.Append( new SCH_TEXT( wxPoint( 0, 0 ), text ) );

pcbnew/exporters/export_hyperlynx.cpp

@@ -585,7 +585,7 @@ bool HYPERLYNX_EXPORTER::Run()
         writePadStacks();
         writeNets();
     }
-    catch( IO_ERROR& err )
+    catch( IO_ERROR& )
     {
         return false;
     }

qa/qa_utils/utility_program.cpp

@@ -47,7 +47,7 @@ UTILITY_PROGRAM::FUNC* COMBINED_UTILITY::findSubUtility( const std::string& aNam
 
         return &prog.m_func;
     }
-    catch( const std::out_of_range& e )
+    catch( const std::out_of_range& )
     {
         // not found in map
     }