selftests: net: separate ipv6_flowlabel_mgr test

The ipv6_flowlabel_mgr used to be a component of a broader overall
flow label test, defined in the ipv6_flowlabel.sh file. This wrapper
script called tests defined on ipv6_flowlabel.c and
ipv6_flowlabel_mgr.c files, using predefined parameters and enforcing
the in_netns.sh helper to set network namespaces for each test env.

However, the ipv6_flowlabel_mgr.c was drastically changed recently.
These modifications led to the mgr tests becoming a self contained and
independent test suite, enforcing netns creation by itself and
not relying on the ipv6_flowlabel.sh wrapper for proper test execution
anymore. Therefore, remove the mgr tests from the wrapper and update
the Makefile to handle it as a standalone test program instead.

Signed-off-by: Marcelo Mendes Spessoto Junior <marcelomspessoto@gmail.com>
Reviewed-by: Hangbin Liu <liuhangbin@kylinos.cn>
Link: https://patch.msgid.link/20260813030708.37609-1-marcelomspessoto@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

tools/testing/selftests/net/Makefile

@@ -150,7 +150,6 @@ TEST_GEN_FILES := \
 	ip_local_port_range \
 	ipsec \
 	ipv6_flowlabel \
-	ipv6_flowlabel_mgr \
 	msg_zerocopy \
 	nettest \
 	psock_fanout \
@@ -183,6 +182,7 @@ TEST_GEN_PROGS := \
 	epoll_busy_poll \
 	getsockopt_iter \
 	icmp_rfc4884 \
+	ipv6_flowlabel_mgr \
 	ipv6_fragmentation \
 	proc_net_pktgen \
 	reuseaddr_conflict \

tools/testing/selftests/net/ipv6_flowlabel.sh

@@ -7,9 +7,6 @@
 
 set -e
 
-echo "TEST management"
-./ipv6_flowlabel_mgr
-
 echo "TEST datapath"
 ./in_netns.sh \
   sh -c 'sysctl -q -w net.ipv6.auto_flowlabels=0 && ./ipv6_flowlabel -l 1'