STM32: Fixed I2C Bug reported in #14696

Modified HAL_I2C_ErrorCallback function to solve bug reported in I2C Driver.
This commit solves compilation error occured when DEVICE_I2CSLAVE is not defined.

Author: affrinpinhero-2356

targets/TARGET_STM/i2c_api.c

@@ -1067,8 +1067,8 @@ void HAL_I2C_ErrorCallback(I2C_HandleTypeDef *hi2c)
     /* Get object ptr based on handler ptr */
     i2c_t *obj = get_i2c_obj(hi2c);
     struct i2c_s *obj_s = I2C_S(obj);
-#if DEVICE_I2CSLAVE
     I2C_HandleTypeDef *handle = &(obj_s->handle);
+#if DEVICE_I2CSLAVE
     uint32_t address = 0;
     /*  Store address to handle it after reset */
     if (obj_s->slave) {