Clean up SEEK_SET definitions.

If we lose the #ifndef, the compiler will tell us if the definitions
of SEEK_SET and friends ever get out of sync.

Change-Id: I357cabec7c9cd451c604342344f210bba20fb6bc
diff --git a/libc/include/stdio.h b/libc/include/stdio.h
index c0dac1a..b04aa24 100644
--- a/libc/include/stdio.h
+++ b/libc/include/stdio.h
@@ -207,16 +207,9 @@
 #define	L_tmpnam	1024	/* XXX must be == PATH_MAX */
 #define	TMP_MAX		308915776
 
-/* Always ensure that these are consistent with <fcntl.h> and <unistd.h>! */
-#ifndef SEEK_SET
-#define	SEEK_SET	0	/* set file offset to offset */
-#endif
-#ifndef SEEK_CUR
-#define	SEEK_CUR	1	/* set file offset to current plus offset */
-#endif
-#ifndef SEEK_END
-#define	SEEK_END	2	/* set file offset to EOF plus offset */
-#endif
+#define SEEK_SET 0
+#define SEEK_CUR 1
+#define SEEK_END 2
 
 /*
  * Functions defined in ANSI C standard.
diff --git a/libc/include/unistd.h b/libc/include/unistd.h
index c755715..6403d4a 100644
--- a/libc/include/unistd.h
+++ b/libc/include/unistd.h
@@ -35,14 +35,19 @@
 #include <sys/select.h>
 #include <sys/sysconf.h>
 
+#include <machine/posix_limits.h>
+
 __BEGIN_DECLS
 
-/* Standard file descriptor numbers. */
 #define STDIN_FILENO	0
 #define STDOUT_FILENO	1
 #define STDERR_FILENO	2
 
-/* Values for whence in fseek and lseek */
+#define F_OK 0
+#define X_OK 1
+#define W_OK 2
+#define R_OK 4
+
 #define SEEK_SET 0
 #define SEEK_CUR 1
 #define SEEK_END 2
@@ -68,8 +73,6 @@
 #define _PC_PRIO_IO 18
 #define _PC_SYNC_IO 19
 
-#include <machine/posix_limits.h>
-
 extern char** environ;
 
 extern __noreturn void _exit(int);
@@ -121,13 +124,6 @@
 extern long fpathconf(int, int);
 extern long pathconf(const char*, int);
 
-
-/* Macros for access() */
-#define R_OK  4  /* Read */
-#define W_OK  2  /* Write */
-#define X_OK  1  /* Execute */
-#define F_OK  0  /* Existence */
-
 extern int access(const char*, int);
 extern int faccessat(int, const char*, int, int);
 extern int link(const char*, const char*);