hal: Resolve compilation errors to enable effects.

Use #ifdef instead of #if in effects related header files
since _cplusplus macro not being defined is raising errors.

Change-Id: I207de40547d99dc98f3130e2514d02a84b485483
diff --git a/qahw_api/inc/qahw_effect_audiosphere.h b/qahw_api/inc/qahw_effect_audiosphere.h
index 2d294de..7bad4b0 100644
--- a/qahw_api/inc/qahw_effect_audiosphere.h
+++ b/qahw_api/inc/qahw_effect_audiosphere.h
@@ -1,4 +1,4 @@
-/* Copyright (c) 2017, The Linux Foundation. All rights reserved.
+/* Copyright (c) 2017-2018, The Linux Foundation. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are
@@ -32,7 +32,7 @@
 
 #include <qahw_effect_api.h>
 
-#if __cplusplus
+#ifdef __cplusplus
 extern "C" {
 #endif
 
@@ -54,7 +54,7 @@
     ASPHERE_PARAM_STATUS,
 } qahw_asphere_params;
 
-#if __cplusplus
+#ifdef __cplusplus
 }  // extern "C"
 #endif
 
diff --git a/qahw_api/inc/qahw_effect_bassboost.h b/qahw_api/inc/qahw_effect_bassboost.h
index 24b02e1..2ca8409 100644
--- a/qahw_api/inc/qahw_effect_bassboost.h
+++ b/qahw_api/inc/qahw_effect_bassboost.h
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2017, The Linux Foundation. All rights reserved.
+ * Copyright (c) 2017-2018, The Linux Foundation. All rights reserved.
  * Not a Contribution.
  *
  * Copyright (C) 2011 The Android Open Source Project
@@ -22,7 +22,7 @@
 
 #include <qahw_effect_api.h>
 
-#if __cplusplus
+#ifdef __cplusplus
 extern "C" {
 #endif
 
@@ -43,7 +43,7 @@
     BASSBOOST_PARAM_STRENGTH
 } qahw_bassboost_params;
 
-#if __cplusplus
+#ifdef __cplusplus
 }  // extern "C"
 #endif
 
diff --git a/qahw_api/inc/qahw_effect_equalizer.h b/qahw_api/inc/qahw_effect_equalizer.h
index 4f9e8f3..fd71c4c 100644
--- a/qahw_api/inc/qahw_effect_equalizer.h
+++ b/qahw_api/inc/qahw_effect_equalizer.h
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2017, The Linux Foundation. All rights reserved.
+ * Copyright (c) 2017-2018, The Linux Foundation. All rights reserved.
  * Not a Contribution.
  *
  * Copyright (C) 2011 The Android Open Source Project
@@ -22,7 +22,7 @@
 
 #include <qahw_effect_api.h>
 
-#if __cplusplus
+#ifdef __cplusplus
 extern "C" {
 #endif
 
@@ -76,7 +76,7 @@
     uint16_t bandLevels[];
 } qahw_equalizer_settings;
 
-#if __cplusplus
+#ifdef __cplusplus
 }  // extern "C"
 #endif
 
diff --git a/qahw_api/inc/qahw_effect_presetreverb.h b/qahw_api/inc/qahw_effect_presetreverb.h
index 1edd0a5..ef3376a 100644
--- a/qahw_api/inc/qahw_effect_presetreverb.h
+++ b/qahw_api/inc/qahw_effect_presetreverb.h
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2017, The Linux Foundation. All rights reserved.
+ * Copyright (c) 2017-2018, The Linux Foundation. All rights reserved.
  * Not a Contribution.
  *
  * Copyright (C) 2011 The Android Open Source Project
@@ -22,7 +22,7 @@
 
 #include <qahw_effect_api.h>
 
-#if __cplusplus
+#ifdef __cplusplus
 extern "C" {
 #endif
 
@@ -59,7 +59,7 @@
     REVERB_PRESET_LAST = REVERB_PRESET_PLATE
 } qahw_reverb_presets;
 
-#if __cplusplus
+#ifdef __cplusplus
 }  // extern "C"
 #endif
 
diff --git a/qahw_api/inc/qahw_effect_virtualizer.h b/qahw_api/inc/qahw_effect_virtualizer.h
index 73af232..5ff95ce 100644
--- a/qahw_api/inc/qahw_effect_virtualizer.h
+++ b/qahw_api/inc/qahw_effect_virtualizer.h
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2017, The Linux Foundation. All rights reserved.
+ * Copyright (c) 2017-2018, The Linux Foundation. All rights reserved.
  * Not a Contribution.
  *
  * Copyright (C) 2011 The Android Open Source Project
@@ -22,7 +22,7 @@
 
 #include <qahw_effect_api.h>
 
-#if __cplusplus
+#ifdef __cplusplus
 extern "C" {
 #endif
 
@@ -78,7 +78,7 @@
     VIRTUALIZER_PARAM_VIRTUALIZATION_MODE
 } qahw_virtualizer_params;
 
-#if __cplusplus
+#ifdef __cplusplus
 }  // extern "C"
 #endif