Fix NREC command format error

Add = sign before off
bug 7326510

Change-Id: Ief269f608646acaa2872679a5c649da3cf22de37
diff --git a/src/com/android/bluetooth/hfp/HeadsetStateMachine.java b/src/com/android/bluetooth/hfp/HeadsetStateMachine.java
index b4f637c..f2587d8 100755
--- a/src/com/android/bluetooth/hfp/HeadsetStateMachine.java
+++ b/src/com/android/bluetooth/hfp/HeadsetStateMachine.java
@@ -1492,7 +1492,7 @@
         if (enable == 1) {
             mAudioManager.setParameters(HEADSET_NREC + "=on");
         } else {
-            mAudioManager.setParameters(HEADSET_NREC + "off");
+            mAudioManager.setParameters(HEADSET_NREC + "=off");
         }
     }