include/elf.h: update for ELFOSABI_* changes.

ELFOSABI_GNU replaces ELFOSABI_LINUX, the latter is kept as a compatibility
alias, and ELFOSABI_HURD is removed.  See the table on
<http://www.sco.com/developers/gabi/latest/ch4.eheader.html#osabi> for
reference.

Signed-off-by: Thomas Schwinge <thomas@codesourcery.com>
Signed-off-by: Bernhard Reutner-Fischer <rep.dot.nop@gmail.com>

include/elf.h

@@ -148,8 +148,8 @@ typedef struct
 #define ELFOSABI_SYSV		0	/* Alias.  */
 #define ELFOSABI_HPUX		1	/* HP-UX */
 #define ELFOSABI_NETBSD		2	/* NetBSD.  */
-#define ELFOSABI_LINUX		3	/* Linux.  */
-#define ELFOSABI_HURD		4	/* GNU/Hurd */
+#define ELFOSABI_GNU		3	/* Object uses GNU ELF extensions.  */
+#define ELFOSABI_LINUX		ELFOSABI_GNU	/* Compatibility alias.  */
 #define ELFOSABI_SOLARIS	6	/* Sun Solaris.  */
 #define ELFOSABI_AIX		7	/* IBM AIX.  */
 #define ELFOSABI_IRIX		8	/* SGI Irix.  */