Fixed typo in interrupt test

software/common/demos/interrupt_demo.c

@@ -209,7 +209,7 @@ void UartExample(void)
   NVIC_DisableIRQ(EXP1_IRQn); // NVIC_DisableIRQ(UARTTX0_IRQn);   -disable both UART0 TX and UART1 RX IRQs
   NVIC_DisableIRQ(EXP2_IRQn); // NVIC_DisableIRQ(UARTRX1_IRQn);
 
- -return;
+  return;
 }
 
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