kcsan: Fold panic() call into print_report()

So that we can add more callers of print_report(), lets fold the panic()
call into print_report() so the caller doesn't have to handle this
explicitly.

There should be no functional change as a result of this patch.

Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Marco Elver <elver@google.com>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>