bpf, doc: Change right arguments for JIT example code

The example code for the x86_64 JIT uses the wrong arguments when
calling function bar().
Signed-off-by: NMao Wenan <maowenan@huawei.com>
Signed-off-by: NDaniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20191114034351.162740-1-maowenan@huawei.com

Documentation/networking/filter.txt

@@ -770,10 +770,10 @@ Some core changes of the new internal format:
     callq foo
     mov %rax,%r13
     mov %rbx,%rdi
-    mov $0x2,%esi
-    mov $0x3,%edx
-    mov $0x4,%ecx
-    mov $0x5,%r8d
+    mov $0x6,%esi
+    mov $0x7,%edx
+    mov $0x8,%ecx
+    mov $0x9,%r8d
     callq bar
     add %r13,%rax
     mov -0x228(%rbp),%rbx