Switch usb_linux_client to C++.

Change-Id: I8172e81e6c4665aa16e9e8e0c33b048dbb9ad848
diff --git a/adb/Android.mk b/adb/Android.mk
index 8a99e6b..01ccbd9 100644
--- a/adb/Android.mk
+++ b/adb/Android.mk
@@ -48,7 +48,7 @@
     usb_windows.cpp \
 
 include $(CLEAR_VARS)
-LOCAL_CLANG := $(ADB_CLANG)
+LOCAL_CLANG := true
 LOCAL_MODULE := libadbd
 LOCAL_CFLAGS := $(LIBADB_CFLAGS) -DADB_HOST=0
 LOCAL_SRC_FILES := \
@@ -57,7 +57,7 @@
     fdevent.cpp \
     jdwp_service.cpp \
     qemu_tracing.cpp \
-    usb_linux_client.c \
+    usb_linux_client.cpp \
 
 include $(BUILD_STATIC_LIBRARY)