Remove RETURN VALUES section for function with return type void.

Closes issue #269.

man/zip_source_rollback_write.mdoc

diff --git a/man/zip_source_rollback_write.mdoc b/man/zip_source_rollback_write.mdoc
index 50a2a60..9d6ab8d 100644
--- a/man/zip_source_rollback_write.mdoc
+++ b/man/zip_source_rollback_write.mdoc
@@ -29,7 +29,7 @@
 .\" OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN
 .\" IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 .\"
-.Dd December 18, 2017
+.Dd November 3, 2021
 .Dt ZIP_SOURCE_ROLLBACK_WRITE 3
 .Os
 .Sh NAME
@@ -50,11 +50,6 @@
 .Xr zip_source_begin_write 3
 was called.
 Usually this removes temporary files or frees buffers.
-.Sh RETURN VALUES
-Upon successful completion 0 is returned.
-Otherwise, \-1 is returned and the error information in
-.Ar source
-is set to indicate the error.
 .Sh SEE ALSO
 .Xr libzip 3 ,
 .Xr zip_source 3 ,