Fix const sp<>& in parameter list and return value

EffectModule::addHandle and Client::heap() were declared incorrectly.

As a parameter, an sp<> should be & for efficiency, and for input
parameters it should also be const to protect the caller's value.

But as a return value, an sp<> should have neither const or &.  The "e"
in "return e;" might be located on the stack, and if there is "&" then
the caller would see the address of a variable which no longer exists.
Also, an & would make it hard to do "return 0;".
A "const" without & is meaningless in the return type.
(In this particular case, the "e" is a member field, so it was safe.)

Change-Id: I3df5f294214eb15a9d4d596c6d5ef29de97b5c27
diff --git a/services/audioflinger/AudioFlinger.cpp b/services/audioflinger/AudioFlinger.cpp
index 2d856ad..518550c 100644
--- a/services/audioflinger/AudioFlinger.cpp
+++ b/services/audioflinger/AudioFlinger.cpp
@@ -4065,7 +4065,7 @@
     mAudioFlinger->removeClient_l(mPid);
 }
 
-const sp<MemoryDealer>& AudioFlinger::Client::heap() const
+sp<MemoryDealer> AudioFlinger::Client::heap() const
 {
     return mMemoryDealer;
 }
@@ -6179,7 +6179,7 @@
     }
 }
 
-status_t AudioFlinger::EffectModule::addHandle(sp<EffectHandle>& handle)
+status_t AudioFlinger::EffectModule::addHandle(const sp<EffectHandle>& handle)
 {
     status_t status;