Style(9) cleanup to src/sys/vfs, stage 17/21: udf.

Style(9) cleanup to src/sys/vfs, stage 17/21: udf.

- Convert K&R-style function definitions to ANSI style.

Note: I chose to leave the formatting of the existing ANSI declarations
alone, as changes to them would mess up the alignment of the associated
comments and the net effect would fail to make the source any more
readable.  A future cleanup could move these comments into the comment
blocks preceding each function definition.

Submitted-by: Andre Nathan <andre@digirati.com.br>
Additional-reformatting-by: cpressey