Since pr_debug() has changed from a macro to an inline function when
DEBUG is not defined, its arguments now need to be defined even when
debugging is off.  Therefore to_event_str() and to_qp_state_str() need
to be moved out of #ifdef DEBUG.  The compiler will throw the
definitions away if DEBUG is not defined, but it needs to be able to
see that the functions exist.

Signed-off-by: Roland Dreier <rolandd@cisco.com>