Drop the dead C_LossOfControl gate

The LOSS_OF_CONTROL_ADDED/UPDATE registration was wrapped in a
`type(C_LossOfControl) == "table"` check, to keep an older ClassicAPI without
the namespace from erroring on an unknown event. That can't happen:
C_LossOfControl ships in v1.10.0, and the addon refuses to finish loading below
v1.15.0. Same shape as the health/power fallbacks removed just before this.

GetSchoolLockout's comment claimed it "Returns 0 for a client without
C_LossOfControl", which was not merely obsolete but wrong -- the function
indexes C_LossOfControl unguarded on its first line, so a missing namespace
raises rather than returning 0. The sentence describes a guard that was never
there.

Left alone: the C_Macro.SetMacroDisplay feature-detect in Init.lua looks like
the same pattern but isn't. SetMacroDisplay lands in v1.15.0, exactly the floor,
so a nil there means the client mod is absent outright, and the flag doubles as
the internal "may we publish" guard that ReleaseDisplays clears.

ClassicAPI.lua

@@ -247,8 +247,8 @@ end
 -- Pummel / Earth Shock lockout) on the player, or 0 when not kicked. Read from
 -- C_LossOfControl, which synthesizes the lockout from the server's own
 -- SMSG_SPELL_COOLDOWN packet -- a state no debuff scan can see. Also returns the
--- seconds remaining (nil if ClassicAPI didn't observe the applying cast). Returns
--- 0 for a client without C_LossOfControl. Player-only (vanilla LoC is local-only).
+-- seconds remaining (nil if ClassicAPI didn't observe the applying cast).
+-- Player-only (vanilla LoC is local-only).
 function API.GetSchoolLockout()
     local n = C_LossOfControl.GetActiveLossOfControlDataCount() or 0
     for i = 1, n do