Add checkpatch.pl to presubmit tests.

Change-Id: I235ea140f5f54dc8b22f1c69dcff5e99a34ff602
diff --git a/inc/hf/std.h b/inc/hf/std.h
index 39d3d08..c872fd4 100644
--- a/inc/hf/std.h
+++ b/inc/hf/std.h
@@ -65,8 +65,12 @@
 #define htole32(v) __builtin_bswap32(v)
 #define htole64(v) __builtin_bswap64(v)
 
-#else /* __BYTE_ORDER__ != __ORDER_LITTLE_ENDIAN__ && \
-	 __BYTE_ORDER__ != __ORDER_BIG_ENDIAN__ */
+#else
+
+/*
+ * __BYTE_ORDER__ != __ORDER_LITTLE_ENDIAN__ &&
+ * __BYTE_ORDER__ != __ORDER_BIG_ENDIAN__
+ */
 
 #error "Unsupported byte order"