libbinder: remove dead attempt inc code

Not used, came up over email recently.

Bug: N/A
Test: N/A
Change-Id: Ibde57ce5607587254a3d9262ac429488f3a5d263

Author: Steven Moreland

libs/binder/IPCThreadState.cpp

@@ -922,28 +922,10 @@ void IPCThreadState::decWeakHandle(int32_t handle)
     flushIfNeeded();
 }
 
-status_t IPCThreadState::attemptIncStrongHandle(int32_t handle)
-{
-#if HAS_BC_ATTEMPT_ACQUIRE
-    LOG_REMOTEREFS("IPCThreadState::attemptIncStrongHandle(%d)\n", handle);
-    mOut.writeInt32(BC_ATTEMPT_ACQUIRE);
-    mOut.writeInt32(0); // xxx was thread priority
-    mOut.writeInt32(handle);
-    status_t result = UNKNOWN_ERROR;
-
-    waitForResponse(NULL, &result);
-
-#if LOG_REFCOUNTS
-    ALOGV("IPCThreadState::attemptIncStrongHandle(%ld) = %s\n",
-        handle, result == NO_ERROR ? "SUCCESS" : "FAILURE");
-#endif
-
-    return result;
-#else
+status_t IPCThreadState::attemptIncStrongHandle(int32_t handle) {
     (void)handle;
     ALOGE("%s(%d): Not supported\n", __func__, handle);
     return INVALID_OPERATION;
-#endif
 }
 
 void IPCThreadState::expungeHandle(int32_t handle, IBinder* binder)