IB/mthca: Don't print debugging info until we have all values

When debugging is enabled, the mthca_QUERY_DEV_LIM() firmware command
function prints out some of the device limits that it queries.
However the debugging prints happen before all of the fields are
extracted from the firmware response, so some of the values that get
printed are uninitialized junk.  Move the prints to the end of the
function to fix this.

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