HAL: msm89{16,74} cleanup mixer on platform deinit

Avoid leaking mixer file descriptor resources. Those leaks were breaking
the VTS tests.

Test: vts-tradefed run vts --module VtsHalAudioV2_0Target
Test: call/play music/record/video...
Bug: 36311550
Change-Id: Ibacab6a988cf8fb1541a74ed875139e23e12c8d8
Signed-off-by: Kevin Rocard <krocard@google.com>
diff --git a/hal/msm8916/platform.c b/hal/msm8916/platform.c
index 65600ee..2fe6168 100644
--- a/hal/msm8916/platform.c
+++ b/hal/msm8916/platform.c
@@ -1054,6 +1054,7 @@
         free(info_item);
     }
 
+    mixer_close(my_data->adev->mixer);
     free(platform);
 }
 
diff --git a/hal/msm8974/platform.c b/hal/msm8974/platform.c
index 7bbf168..0f3bcf0 100644
--- a/hal/msm8974/platform.c
+++ b/hal/msm8974/platform.c
@@ -1483,6 +1483,7 @@
         free(info_item);
     }
 
+    mixer_close(my_data->adev->mixer);
     free(platform);
 
     /* deinit usb */