mlx4_core: Fix unused variable warning

Fix

   drivers/net/mlx4/profile.c:55: warning: 'res_name' defined but not used

by making mlx4_dbg() always use all of its parameters, regardless of
whether CONFIG_MLX4_DEBUG is set or not.

Reported-by: Alexander Beregalov <a.beregalov@gmail.com>
Signed-off-by: Roland Dreier <rolandd@cisco.com>