x86-64: Remove vsyscall number 3 (venosys)

It just segfaults since April 2008 (a4928cff), so I'm pretty
sure that nothing uses it.  And having an empty section makes
the linker script a bit fragile.
Signed-off-by: Andy Lutomirski <luto@mit.edu>
Cc: Jesper Juhl <jj@chaosbits.net>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Arjan van de Ven <arjan@infradead.org>
Cc: Jan Beulich <JBeulich@novell.com>
Cc: richard -rw- weinberger <richard.weinberger@gmail.com>
Cc: Mikael Pettersson <mikpe@it.uu.se>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Louis Rilling <Louis.Rilling@kerlabs.com>
Cc: Valdis.Kletnieks@vt.edu
Cc: pageexec@freemail.hu
Link: http://lkml.kernel.org/r/4a4abcf47ecadc269f2391a313576fe6d06acef7.1307292171.git.luto@mit.eduSigned-off-by: Ingo Molnar <mingo@elte.hu>

arch/x86/kernel/vmlinux.lds.S

@@ -182,10 +182,6 @@ SECTIONS
 		*(.vsyscall_2)
 	}
 
-	.vsyscall_3 ADDR(.vsyscall_0) + 3072: AT(VLOAD(.vsyscall_3)) {
-		*(.vsyscall_3)
-	}
-
 	. = ALIGN(__vsyscall_0 + PAGE_SIZE, PAGE_SIZE);
 
 #undef VSYSCALL_ADDR

arch/x86/kernel/vsyscall_64.c

@@ -209,11 +209,6 @@ vgetcpu(unsigned *cpu, unsigned *node, struct getcpu_cache *tcache)
 	return 0;
 }
 
-static long __vsyscall(3) venosys_1(void)
-{
-	return -ENOSYS;
-}
-
 /* Assume __initcall executes before all user space. Hopefully kmod
    doesn't violate that. We'll find out if it does. */
 static void __cpuinit vsyscall_set_cpu(int cpu)