hal: Compilation fix

Change-Id: I7c259b96f2fb86b8a6ccb1510301f0a67ac80a6a
diff --git a/hal/msm8916/platform.c b/hal/msm8916/platform.c
index 8d7132c..e932667 100644
--- a/hal/msm8916/platform.c
+++ b/hal/msm8916/platform.c
@@ -4345,6 +4345,7 @@
 int platform_set_parameters(void *platform, struct str_parms *parms)
 {
     struct platform_data *my_data = (struct platform_data *)platform;
+    struct audio_device *adev = my_data->adev;
     char value[256] = {0};
     int len;
     int ret = 0, err;