tools/nolibc: Include linux/fcntl.h and remove duplicate code

Include linux/fcntl.h for O_* and AT_*. asm/fcntl.h is included
by linux/fcntl.h, so it can be safely removed.

Signed-off-by: Feiyang Chen <chenfeiyang@loongson.cn>
Acked-by: Huacai Chen <chenhuacai@loongson.cn>
Signed-off-by: Willy Tarreau <w@1wt.eu>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>

tools/include/nolibc/sys.h

@@ -11,7 +11,6 @@
 #include "std.h"
 
 /* system includes */
-#include <asm/fcntl.h>   // for O_*
 #include <asm/unistd.h>
 #include <asm/signal.h>  // for SIGCHLD
 #include <asm/ioctls.h>
@@ -20,6 +19,7 @@
 #include <linux/loop.h>
 #include <linux/time.h>
 #include <linux/auxvec.h>
+#include <linux/fcntl.h> // for O_* and AT_*
 
 #include "arch.h"
 #include "errno.h"

tools/include/nolibc/types.h

@@ -81,11 +81,6 @@
 #define MAXPATHLEN     (PATH_MAX)
 #endif
 
-/* Special FD used by all the *at functions */
-#ifndef AT_FDCWD
-#define AT_FDCWD       (-100)
-#endif
-
 /* whence values for lseek() */
 #define SEEK_SET       0
 #define SEEK_CUR       1