[patch] expr.c: Fix formatting.

[DJ Delorie]

> Well, IMHO, the whole point is to make variable names stand up in
> comments.

No, the whole point is to be able to tell the difference between a
reference to a variable, and a reference to what the variable's value
represents.

Consider this example:

  /* When passing a buffer, if count is non-zero, then at most COUNT
     bytes will be transferred. */

If *I* wanted to make the variable stand out, *I* would do this:

  /* When passing a buffer, if `count' is non-zero, then at most COUNT
     bytes will be transferred. */