Building and electrical codes require the black wire to be "hot" and switched and the white wire to be neutral/ground. By wiring it that way, with the switch on the white wire, you leave it electrified at all times, even when switched off, a dangerous situation for the next guy who might have occasion to fix it. You also set up a possible short path via the ground (green or bare) wire.
My guess is that you burned it out.
If you put it on a GFCI protected circuit, as an exterior light is supposed to be, you certainly kicked the GFCI off.