Fix misplaced parentheses (#12284)

Marlin/src/HAL/HAL_STM32/fastio_STM32.h

@@ -52,7 +52,7 @@ void FastIO_init(); // Must be called before using fast io macros
     else   FastIOPortMap[STM_PORT(digitalPin[IO])]->BRR  = _BV32(STM_PIN(digitalPin[IO])) ; \
   } while(0)
 #else
-  #define _WRITE(IO, V) (FastIOPortMap[STM_PORT(digitalPin[IO])]->BSRR = _BV32(STM_PIN(digitalPin[IO] + (V ? 0 : 16))))
+  #define _WRITE(IO, V) (FastIOPortMap[STM_PORT(digitalPin[IO])]->BSRR = _BV32(STM_PIN(digitalPin[IO]) + (V ? 0 : 16)))
 #endif
 
 #define _READ(IO)               bool(READ_BIT(FastIOPortMap[STM_PORT(digitalPin[IO])]->IDR, _BV32(STM_PIN(digitalPin[IO]))))