Fix the last warnings in frameworks/av/ drm code.

- index is always positive so no need to check > 0
- args parameters are unused.

Bug: 27151704
Change-Id: Ia4c23e1fc4eaef47f38526574b35ccfea9c92177
diff --git a/services/mediadrm/Android.mk b/services/mediadrm/Android.mk
index cc78361..f6ddf94 100644
--- a/services/mediadrm/Android.mk
+++ b/services/mediadrm/Android.mk
@@ -34,6 +34,8 @@
 LOCAL_C_INCLUDES := \
     frameworks/av/media/libmediaplayerservice \
 
+LOCAL_CFLAGS += -Wall -Wextra -Werror
+
 LOCAL_MODULE:= mediadrmserver
 LOCAL_32_BIT_ONLY := true
 
diff --git a/services/mediadrm/main_mediadrmserver.cpp b/services/mediadrm/main_mediadrmserver.cpp
index 4d0b644..b767b8c 100644
--- a/services/mediadrm/main_mediadrmserver.cpp
+++ b/services/mediadrm/main_mediadrmserver.cpp
@@ -30,7 +30,7 @@
 
 using namespace android;
 
-int main(int argc __unused, char** argv)
+int main()
 {
     signal(SIGPIPE, SIG_IGN);