drivers: i2s_mcux_sai: optimize purge_stream

There's no need to put an if before i2s_purge_stream_buffers,
because this is handled already by the boolean values entered to the
function

Also remove the inline of the function, which allowed the compiler to
make optimizations and save some bytes.

Signed-off-by: Declan Snyder <declan.snyder@nxp.com>

Author: decsny

drivers/i2s/i2s_mcux_sai.c

@@ -117,8 +117,8 @@ struct i2s_dev_data {
 	void *rx_out_msgs[CONFIG_I2S_RX_BLOCK_COUNT];
 };
 
-static inline void i2s_purge_stream_buffers(struct stream *strm, struct k_mem_slab *mem_slab,
-					    bool in_drop, bool out_drop)
+static void i2s_purge_stream_buffers(struct stream *strm, struct k_mem_slab *mem_slab, bool in_drop,
+				     bool out_drop)
 {
 	void *buffer;
 
@@ -167,9 +167,7 @@ static void i2s_tx_stream_disable(const struct device *dev, bool drop)
 	}
 
 	/* purge buffers queued in the stream */
-	if (drop) {
-		i2s_purge_stream_buffers(strm, dev_data->tx.cfg.mem_slab, true, true);
-	}
+	i2s_purge_stream_buffers(strm, dev_data->tx.cfg.mem_slab, drop, drop);
 }
 
 static void i2s_rx_stream_disable(const struct device *dev, bool in_drop, bool out_drop)
@@ -200,9 +198,7 @@ static void i2s_rx_stream_disable(const struct device *dev, bool in_drop, bool o
 	dev_cfg->base->RCSR &= ~I2S_RCSR_SR_MASK;
 
 	/* purge buffers queued in the stream */
-	if (in_drop || out_drop) {
-		i2s_purge_stream_buffers(strm, dev_data->rx.cfg.mem_slab, in_drop, out_drop);
-	}
+	i2s_purge_stream_buffers(strm, dev_data->rx.cfg.mem_slab, in_drop, out_drop);
 }
 
 static int i2s_tx_reload_multiple_dma_blocks(const struct device *dev, uint8_t *blocks_queued)