In the Armature drawing code, split up `get_pchan_color()` into three
separate functions. It was basically one big `switch` with three
`case`s, and there were three calls of the function, each with its own
hard-coded parameter value, one for each `case`.
This now also makes it clear that two of those functions always write to
their return parameter, and thus copying a default color 'just in case'
is no longer necessary, reducing the parameter counts even more.
No functional changes.
4aef0204ac