Clean up C-style casts from pointers to void

Change-Id: I5f2240b6ac5210f185081bec891ad6d3f7901679

io/source/stm/opump.cxx

@@ -242,8 +242,8 @@ void Pump::close()
 void Pump::static_run( void* pObject )
 {
     osl_setThreadName("io_stm::Pump::run()");
-    ((Pump*)pObject)->run();
-    ((Pump*)pObject)->release();
+    static_cast<Pump*>(pObject)->run();
+    static_cast<Pump*>(pObject)->release();
 }
 
 void Pump::run()

io/source/stm/streamhelper.cxx

@@ -106,7 +106,7 @@ void MemRingBuffer::resizeBuffer( sal_Int32 nMinSize ) throw( IRingBuffer_OutOfM
     }
 
     if( nNewLen != m_nBufferLen ) {
-        m_p = ( sal_Int8 * ) rtl_reallocateMemory( m_p , nNewLen );
+        m_p = static_cast<sal_Int8 *>(rtl_reallocateMemory( m_p , nNewLen ));
         if( !m_p ) {
             throw IRingBuffer_OutOfMemoryException();
         }