bonding: fix NULL pointer dereference in actor_port_prio setting

Liang reported an issue where setting a slave’s actor_port_prio to
predefined values such as 0, 255, or 65535 would cause a system crash.

The problem occurs because in bond_opt_parse(), when the provided value
matches a predefined table entry, the function returns that table entry,
which does not contain slave information. Later, in
bond_option_actor_port_prio_set(), calling bond_slave_get_rtnl() leads
to a NULL pointer dereference.

Since actor_port_prio is defined as a u16 and initialized to the default
value of 255 in ad_initialize_port(), there is no need for the
bond_actor_port_prio_tbl. Using the BOND_OPTFLAG_RAWVAL flag is sufficient.

Fixes: 6b6dc81ee7e8 ("bonding: add support for per-port LACP actor priority")
Reported-by: Liang Li <[e-mail]>
Signed-off-by: Hangbin Liu <[e-mail]>
Link: https://patch.msgid.link/[e-mail]
Signed-off-by: Jakub Kicinski <[e-mail]>

drivers/net/bonding/bond_options.c

···
 	{ NULL,      -1,    0},
 };
 
-static const struct bond_opt_value bond_actor_port_prio_tbl[] = {
-	{ "minval",  0,     BOND_VALFLAG_MIN},
-	{ "maxval",  65535, BOND_VALFLAG_MAX},
-	{ "default", 255,   BOND_VALFLAG_DEFAULT},
-	{ NULL,      -1,    0},
-};
-
 static const struct bond_opt_value bond_ad_user_port_key_tbl[] = {
 	{ "minval",  0,     BOND_VALFLAG_MIN | BOND_VALFLAG_DEFAULT},
 	{ "maxval",  1023,  BOND_VALFLAG_MAX},
···
 		.id = BOND_OPT_ACTOR_PORT_PRIO,
 		.name = "actor_port_prio",
 		.unsuppmodes = BOND_MODE_ALL_EX(BIT(BOND_MODE_8023AD)),
-		.values = bond_actor_port_prio_tbl,
+		.flags = BOND_OPTFLAG_RAWVAL,
 		.set = bond_option_actor_port_prio_set,
 	},
 	[BOND_OPT_AD_ACTOR_SYSTEM] = {