Fix build for gcc.

Gcc doesn't like the brace object initialization, so make all of
the Feature objects explicit.

Also, no arguments to the error_log macros make gcc unhappy, so add
an option to turn these into warnings. These will be fixed when we
add the explicit _error and _warn log functions.

Change-Id: I35af834dabb5548923e893dd980a751fdebfa13a
diff --git a/libc/malloc_debug/Android.mk b/libc/malloc_debug/Android.mk
index f0f4056..4c2c7f3 100644
--- a/libc/malloc_debug/Android.mk
+++ b/libc/malloc_debug/Android.mk
@@ -37,10 +37,12 @@
 LOCAL_SANITIZE := never
 LOCAL_NATIVE_COVERAGE := false
 
+# -Wno-error=format-zero-length needed for gcc to compile.
 LOCAL_CFLAGS := \
     -Wall \
     -Werror \
     -fno-stack-protector \
+    -Wno-error=format-zero-length \
 
 include $(BUILD_SHARED_LIBRARY)