vcs-svn: a void function shouldn't try to return something

vcs-svn: a void function shouldn't try to return something

As v1.7.4-rc0~184 (2010-10-04) and C99 §6.8.6.4.1 remind us, standard
C does not permit returning an expression of type void, even for a
tail call.

Noticed with gcc -pedantic:

 vcs-svn/svndump.c: In function 'handle_node':
 vcs-svn/svndump.c:213:3: warning: ISO C forbids 'return' with expression,
  in function returning void [-pedantic]

[jn: with simplified log message]

Signed-off-by: Michael Witten <mfwitten@gmail.com>
Signed-off-by: Jonathan Nieder <jrnieder@gmail.com>