Variable in `_get_scaling` is never used

[ricardoV94]

PyCharm tells me this variable is never used:

pymc/pymc/distributions/logprob.py

Line 94 in 4ca3414

coef = 1.0

CC: @ferrine and @chritter

[fonnesbeck]

Looks like there should be an else block for the code below that assignment, representing begin and end lengths that are neither scalar nor too large.