ASoC: qdsp6: q6asm: fix cppcheck warnings for unnecessary initialization

cppcheck reports below warning.
q6asm.c:1631: (style) Variable 'port' is reassigned a value before the
old one has been used.

This is due to unnecessary initialization of variable port, which is
now removed as part of this patch.

Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Link: https://lore.kernel.org/r/20210809123137.14456-2-srinivas.kandagatla@linaro.org
Signed-off-by: Mark Brown <broonie@kernel.org>

sound/soc/qcom/qdsp6/q6asm.c

@@ -1624,7 +1624,7 @@ EXPORT_SYMBOL_GPL(q6asm_write_async);
 
 static void q6asm_reset_buf_state(struct audio_client *ac)
 {
-	struct audio_port_data *port = NULL;
+	struct audio_port_data *port;
 	unsigned long flags;
 
 	spin_lock_irqsave(&ac->lock, flags);