net/ipv6: Remove unnecessary pr_debug() logs

In the ipv6 system, we have some logs basically dumping the name of the
function that is being called. This is not ideal, since ftrace give us
"for free". Moreover, checkpatch is not happy when touching that code:

	WARNING: Unnecessary ftrace-like logging - prefer using ftrace

Remove debug functions that only print the current function name.

Signed-off-by: Breno Leitao <leitao@debian.org>
Reviewed-by: David Ahern <dsahern@kernel.org>
Link: https://lore.kernel.org/r/20240122181955.2391676-1-leitao@debian.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

net/ipv6/ip6_fib.c

@@ -751,8 +751,6 @@ static struct fib6_node *fib6_add_1(struct net *net,
 	int	bit;
 	__be32	dir = 0;
 
-	RT6_TRACE("fib6_add_1\n");
-
 	/* insert node in tree */
 
 	fn = root;
@@ -1905,8 +1903,6 @@ static void fib6_del_route(struct fib6_table *table, struct fib6_node *fn,
 	struct net *net = info->nl_net;
 	bool notify_del = false;
 
-	RT6_TRACE("fib6_del_route\n");
-
 	/* If the deleted route is the first in the node and it is not part of
 	 * a multipath route, then we need to replace it with the next route
 	 * in the node, if exists.