Fixed nasty compiler warnings.

backend/plustek-pp_tpa.c

@@ -839,6 +839,8 @@ _LOC void TPAP98003Reshading( pScanData ps )
     DataPointer RedPtr, GreenPtr, BluePtr;
     TimerDef    timer;
 
+	bHi[0] = bHi[1] = bHi[2] = 0;
+
 /* CHECK: Why this ??? */
 #if 1
     ps->Scan.negScan[1].exposureTime = 144;

backend/u12-tpa.c

@@ -62,6 +62,8 @@ static void u12tpa_Reshading( U12_Device *dev )
 
 	DBG( _DBG_INFO, "u12tpa_Reshading()\n" );
 
+	bHi[0] = bHi[1] = bHi[2] = 0;
+
 	dev->scan.negScan[1].exposureTime = 144;
 	dev->scan.negScan[1].xStepTime    = 18;
 	dev->scan.negScan[2].exposureTime = 144;