Switch netd's last C file to C++.

(I stumbled into this in the my "who needs _GNU_SOURCE?" investigation.)

Change-Id: Ie4e69802bdea3c5e462f68916dc05b8617642e2b
diff --git a/server/Android.mk b/server/Android.mk
index b713b4f..cce4503 100644
--- a/server/Android.mk
+++ b/server/Android.mk
@@ -85,6 +85,6 @@
 LOCAL_CLANG := true
 LOCAL_MODULE := ndc
 LOCAL_SHARED_LIBRARIES := libcutils
-LOCAL_SRC_FILES := ndc.c
+LOCAL_SRC_FILES := ndc.cpp
 
 include $(BUILD_EXECUTABLE)
diff --git a/server/ndc.c b/server/ndc.cpp
similarity index 98%
rename from server/ndc.c
rename to server/ndc.cpp
index 00fb77c..14f6654 100644
--- a/server/ndc.c
+++ b/server/ndc.cpp
@@ -115,7 +115,7 @@
 }
 
 static int do_monitor(int sock, int stop_after_cmd) {
-    char *buffer = malloc(4096);
+    char *buffer = (char *)malloc(4096);
 
     if (!stop_after_cmd)
         printf("[Connected to Netd]\n");