Use -Werror in hardware/intel/common/libwsbm/src

Bug: 66996870
Test: build with WITH_TIDY=1
Change-Id: Ib34ea4b9da0cddc2173eb241a4e872b5adce613a
diff --git a/src/Android.mk b/src/Android.mk
index a049c9d..1482056 100644
--- a/src/Android.mk
+++ b/src/Android.mk
@@ -14,6 +14,7 @@
    wsbm_userpool.c
 
 LOCAL_CFLAGS += -DHAVE_CONFIG_H
+LOCAL_CFLAGS += -Wall -Werror
 LOCAL_C_INCLUDES :=            \
    $(LOCAL_PATH)/../       \
    $(TARGET_OUT_HEADERS)/drm \