bpf: Change func bpf_iter_unreg_target() signature

Change func bpf_iter_unreg_target() parameter from target
name to target reg_info, similar to bpf_iter_reg_target().

Signed-off-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Andrii Nakryiko <andriin@fb.com>
Link: https://lore.kernel.org/bpf/20200513180220.2949737-1-yhs@fb.com
diff --git a/net/ipv6/route.c b/net/ipv6/route.c
index 6ad2fa5..22bf4e3 100644
--- a/net/ipv6/route.c
+++ b/net/ipv6/route.c
@@ -6412,7 +6412,7 @@ static int __init bpf_iter_register(void)
 
 static void bpf_iter_unregister(void)
 {
-	bpf_iter_unreg_target("ipv6_route");
+	bpf_iter_unreg_target(&ipv6_route_reg_info);
 }
 #endif
 #endif