panic: call console_verbose() in panic

Most distros turn the console verbosity down and that means a backtrace
after a panic never makes it to the console.  I assume we haven't seen
this because a panic is often preceeded by an oops which will have called
console_verbose.  There are however a lot of places we call panic
directly, and they are broken.

Use console_verbose like we do in the oops path to ensure a directly
called panic will print a backtrace.

Signed-off-by: Anton Blanchard <anton@samba.org>
Acked-by: Greg Kroah-Hartman <gregkh@suse.de>
Cc: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

kernel/panic.c

@@ -87,6 +87,7 @@ NORET_TYPE void panic(const char * fmt, ...)
 	 */
 	preempt_disable();
 
+	console_verbose();
 	bust_spinlocks(1);
 	va_start(args, fmt);
 	vsnprintf(buf, sizeof(buf), fmt, args);