Revert "tools: ffs-test: convert to new descriptor format fixing compilation error"

This reverts commit f2af74123f8c5a735248547f4286a3adc28633c1.

There is a better fix for this build error coming in a following
patch.

Signed-of-by: Felipe Balbi <[e-mail]>

include/uapi/linux/usb/functionfs.h

···
  * structure.  Any flags that are not recognised cause the whole block to be
  * rejected with -ENOSYS.
  *
- * Legacy descriptors format (deprecated as of 3.14):
+ * Legacy descriptors format:
  *
  * | off | name      | type         | description                          |
  * |-----+-----------+--------------+--------------------------------------|

tools/usb/Makefile

···
 CFLAGS = $(WARNINGS) -g -I../include
 LDFLAGS = $(PTHREAD_LIBS)
 
-all: testusb ffs-test ffs-test-legacy
-
-ffs-test-legacy: ffs-test.c
-	$(CC) $(CFLAGS) -o $@ $^ $(LDFLAGS) -DUSE_LEGACY_DESC_HEAD
-
+all: testusb ffs-test
 %: %.c
 	$(CC) $(CFLAGS) -o $@ $^ $(LDFLAGS)
 

tools/usb/ffs-test.c

···
 /*
- * ffs-test.c -- user mode filesystem api for usb composite function
+ * ffs-test.c.c -- user mode filesystem api for usb composite function
  *
  * Copyright (C) 2010 Samsung Electronics
  *                    Author: Michal Nazarewicz <[e-mail]>
···
 
 /* $(CROSS_COMPILE)cc -Wall -Wextra -g -o ffs-test ffs-test.c -lpthread */
 
-/* Uncomment to make the tool use legacy FFS descriptor headers. */
-/* #define USE_LEGACY_DESC_HEAD */
 
 #define _BSD_SOURCE /* for endian.h */
 
···
 /******************** Descriptors and Strings *******************************/
 
 static const struct {
-	struct {
-		__le32 magic;
-		__le32 length;
-#ifndef USE_LEGACY_DESC_HEAD
-		__le32 flags;
-#endif
-		__le32 fs_count;
-		__le32 hs_count;
-	} __attribute__((packed)) header;
+	struct usb_functionfs_descs_head header;
 	struct {
 		struct usb_interface_descriptor intf;
 		struct usb_endpoint_descriptor_no_audio sink;
···
 	} __attribute__((packed)) fs_descs, hs_descs;
 } __attribute__((packed)) descriptors = {
 	.header = {
-#ifdef USE_LEGACY_DESC_HEAD
 		.magic = cpu_to_le32(FUNCTIONFS_DESCRIPTORS_MAGIC),
-#else
-		.magic = cpu_to_le32(FUNCTIONFS_DESCRIPTORS_MAGIC_V2),
-		.flags = cpu_to_le32(FUNCTIONFS_HAS_FS_DESC |
-				     FUNCTIONFS_HAS_HS_DESC),
-#endif
 		.length = cpu_to_le32(sizeof descriptors),
 		.fs_count = 3,
 		.hs_count = 3,