vfs: use UAPI types for new struct delegation definition

Using libc types and headers from the UAPI headers is problematic as it
introduces a dependency on a full C toolchain.

Use the fixed-width integer types provided by the UAPI headers instead.

Fixes: 1602bad ("vfs: expose delegation support to userland")
Fixes: 4be9e04 ("vfs: add needed headers for new struct delegation definition")
Signed-off-by: Thomas Weißschuh <thomas.weissschuh@linutronix.de>
Link: https://patch.msgid.link/20251203-uapi-fcntl-v1-1-490c67bf3425@linutronix.de
Acked-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Christian Brauner <brauner@kernel.org>

Author: t-8ch

include/uapi/linux/fcntl.h

@@ -4,11 +4,7 @@
 
 #include <asm/fcntl.h>
 #include <linux/openat2.h>
-#ifdef __KERNEL__
 #include <linux/types.h>
-#else
-#include <stdint.h>
-#endif
 
 #define F_SETLEASE	(F_LINUX_SPECIFIC_BASE + 0)
 #define F_GETLEASE	(F_LINUX_SPECIFIC_BASE + 1)
@@ -90,9 +86,9 @@
 
 /* Argument structure for F_GETDELEG and F_SETDELEG */
 struct delegation {
-	uint32_t	d_flags;	/* Must be 0 */
-	uint16_t	d_type;		/* F_RDLCK, F_WRLCK, F_UNLCK */
-	uint16_t	__pad;		/* Must be 0 */
+	__u32	d_flags;	/* Must be 0 */
+	__u16	d_type;		/* F_RDLCK, F_WRLCK, F_UNLCK */
+	__u16	__pad;		/* Must be 0 */
 };
 
 /*