fixed formatting

Author: torfjelde

src/interface.jl

@@ -86,7 +86,9 @@ standard iteration.
 By default, this simply calls [`AbstractMCMC.step`](@ref).
 """
 step_warmup(rng, model, sampler; kwargs...) = step(rng, model, sampler; kwargs...)
-step_warmup(rng, model, sampler, state; kwargs...) = step(rng, model, sampler, state; kwargs...)
+function step_warmup(rng, model, sampler, state; kwargs...)
+    return step(rng, model, sampler, state; kwargs...)
+end
 
 """
     samples(sample, model, sampler[, N; kwargs...])