tftp: remove definitions that can be included from system header

This will cause the following warning when _FORTIFY_SOURCE= is in use.  The
warning is explained in glibc.  In short that is fine.

/usr/include/bits/string_fortified.h:90:10: warning: ‘__builtin___strcpy_chk’
writing 1 or more bytes into a region of size 0 overflows the destination
[-Wstringop-overflow=]
   return __builtin___strcpy_chk (__dest, __src, __bos (__dest));

Reference: http://www.sourceware.org/git/gitweb.cgi?p=glibc.git;a=commitdiff;h=abb66a672f5575a328d05c0790403af673d0f76c
Signed-off-by: Sami Kerola <kerolasa@iki.fi>

tftp.h

@@ -29,49 +29,7 @@
 
 #define	PKTSIZE	SEGSIZE+4
 
-#ifndef _ARPA_TFTP_H
-#define _ARPA_TFTP_H
-/*
- * Trivial File Transfer Protocol (IEN-133)
- */
-#define	SEGSIZE		512		/* data segment size */
-
-/*
- * Packet types.
- */
-#define	RRQ	01			/* read request */
-#define	WRQ	02			/* write request */
-#define	DATA	03			/* data packet */
-#define	ACK	04			/* acknowledgement */
-#define	ERROR	05			/* error code */
-
-struct	tftphdr {
-	short	th_opcode;		/* packet type */
-	union {
-		short	tu_block;	/* block # */
-		short	tu_code;	/* error code */
-		char	tu_stuff[1];	/* request packet stuff */
-	} th_u;
-	char	th_data[1];		/* data or error string */
-};
-
-#define	th_block	th_u.tu_block
-#define	th_code		th_u.tu_code
-#define	th_stuff	th_u.tu_stuff
-#define	th_msg		th_data
-
-/*
- * Error codes.
- */
-#define	EUNDEF		0		/* not defined */
-#define	ENOTFOUND	1		/* file not found */
-#define	EACCESS		2		/* access violation */
-#define	ENOSPACE	3		/* disk full or allocation exceeded */
-#define	EBADOP		4		/* illegal TFTP operation */
-#define	EBADID		5		/* unknown transfer ID */
-#define	EEXISTS		6		/* file already exists */
-#define	ENOUSER		7		/* no such user */
-
+#include <arpa/tftp.h>
 
 extern int readit(FILE * file, struct tftphdr **dpp, int convert);
 extern void read_ahead(FILE *file, int convert);
@@ -80,6 +38,3 @@ extern int write_behind(FILE *file, int convert);
 extern int synchnet(int f);
 extern struct tftphdr *w_init(void);
 extern struct tftphdr *r_init(void);
-
-
-#endif /* _ARPA_TFTP_H */