Update the sys tick to be more efficient.

Source/portable/GCC/ARM_CM3/port.c

@@ -262,12 +262,12 @@ void xPortPendSVHandler( void )
 
 void xPortSysTickHandler( void )
 {
-	vTaskIncrementTick();
-	
 	/* If using preemption, also force a context switch. */
 	#if configUSE_PREEMPTION == 1
 		*(portNVIC_INT_CTRL) |= portNVIC_PENDSVSET;	
 	#endif
+
+	vTaskIncrementTick();
 }
 /*-----------------------------------------------------------*/
 

Source/portable/IAR/ARM_CM3/port.c

@@ -184,12 +184,12 @@ void vPortExitCritical( void )
 
 void xPortSysTickHandler( void )
 {
-	vTaskIncrementTick();
-	
 	/* If using preemption, also force a context switch. */
 	#if configUSE_PREEMPTION == 1
 		*(portNVIC_INT_CTRL) |= portNVIC_PENDSVSET;	
 	#endif
+
+	vTaskIncrementTick();
 }
 /*-----------------------------------------------------------*/
 

Source/portable/RVDS/ARM_CM3/port.c

@@ -243,12 +243,12 @@ sv_disable_interrupts
 
 void xPortSysTickHandler( void )
 {
-	vTaskIncrementTick();
-	
 	/* If using preemption, also force a context switch. */
 	#if configUSE_PREEMPTION == 1
 		*(portNVIC_INT_CTRL) |= portNVIC_PENDSVSET;	
 	#endif
+
+	vTaskIncrementTick();
 }
 /*-----------------------------------------------------------*/