LibC: Redefine SEEK_* macros to match common systems

some ports written in assembly seem to depend on this

userspace/libraries/LibC/include/fcntl.h

@@ -32,9 +32,9 @@ __BEGIN_DECLS
 #define F_WRLCK 3
 
 // NOTE: also defined in stdio.h
-#define SEEK_SET 1
-#define SEEK_CUR 2
-#define SEEK_END 3
+#define SEEK_SET 0
+#define SEEK_CUR 1
+#define SEEK_END 2
 
 /* bits 0-3 */
 #define O_RDONLY	0x00001

userspace/libraries/LibC/include/stdio.h

@@ -35,9 +35,9 @@ typedef off_t fpos_t;
 #define _IONBF 3
 
 // NOTE: also defined in fcntl.h
-#define SEEK_SET 1
-#define SEEK_CUR 2
-#define SEEK_END 3
+#define SEEK_SET 0
+#define SEEK_CUR 1
+#define SEEK_END 2
 
 #define FILENAME_MAX 256
 #define FOPEN_MAX 16