panic: clean up message about deprecated 'panic_print' parameter

panic: clean up message about deprecated 'panic_print' parameter

Remove duplication of the message about deprecated 'panic_print'
parameter.

Also make the wording more direct.  Make it clear that the new parameters
already exist and should be used instead.

Link: https://lkml.kernel.org/r/20250825025701.81921-5-feng.tang@linux.alibaba.com
Signed-off-by: Petr Mladek <pmladek@suse.com>
Signed-off-by: Feng Tang <feng.tang@linux.alibaba.com>
Reviewed-by: Lance Yang <lance.yang@linux.dev>
Tested-by: Lance Yang <lance.yang@linux.dev>
Reviewed-by: Feng Tang <feng.tang@linux.alibaba.com>
Cc: Askar Safin <safinaskar@zohomail.com>
Cc: John Ogness <john.ogness@linutronix.de>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: "Paul E . McKenney" <paulmck@kernel.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>