Evaluate the following expression, then ask for help with ?.

(read-multiple-choice  "Choose:"
		       '((?a "aaa")
			 (?b "bbb")
			 (?c "ccc" "a really long description of ccc")))

The description of choice "ccc" is misaligned in the help buffer:
------
Choose:

a: aaa                   b: bbb                   c: ccc
                                                  a really long
description of ccc
------

I expect the help buffer to look something like this:
------
Choose:

a: aaa                   b: bbb                   c: ccc
                                                  a really long
                                                  description of ccc
------

The patch below solves the problem, but I'm sure, it can be improved.
Additionally, I've attempted to write a test for this.

Thanks.