Remove sentences in RETURN VALUES sections saying that functions with

void return types 'return no value'. This is obvious and therefore
unneccessary to mention.
We spare rewind(3)'s sentence because espie@ pointed out that it's a
warning - the function masks a potential error.
This commit also adds a sentence to X509_free clarifying that it's
NULL-safe. This bit was discussed with doug@.
ok martijn@, sentiment supported by schwarze@

src/lib/libc/stdlib/hcreate.3

@@ -1,4 +1,4 @@
-.\" 	$OpenBSD: hcreate.3,v 1.6 2010/07/28 09:00:20 ray Exp $
+.\" 	$OpenBSD: hcreate.3,v 1.7 2016/03/12 21:31:22 mmcc Exp $
 .\" 	$NetBSD: hcreate.3,v 1.8 2010/05/01 06:18:03 jruoho Exp $
 .\"
 .\" Copyright (c) 1999 The NetBSD Foundation, Inc.
@@ -28,7 +28,7 @@
 .\" ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 .\" POSSIBILITY OF SUCH DAMAGE.
 .\"
-.Dd $Mdocdate: July 28 2010 $
+.Dd $Mdocdate: March 12 2016 $
 .Dt HCREATE 3
 .Os
 .Sh NAME
@@ -159,11 +159,6 @@ Otherwise, a value of 0 is returned and
 .Va errno
 is set to indicate the error.
 .Pp
-The
-.Fn hdestroy
-functions
-returns no value.
-.Pp
 If successful, the
 .Fn hsearch
 function returns a pointer to a hash table entry matching

src/lib/libc/stdlib/malloc.3

@@ -30,9 +30,9 @@
 .\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 .\" SUCH DAMAGE.
 .\"
-.\"	$OpenBSD: malloc.3,v 1.93 2016/02/05 15:09:09 schwarze Exp $
+.\"	$OpenBSD: malloc.3,v 1.94 2016/03/12 21:31:22 mmcc Exp $
 .\"
-.Dd $Mdocdate: February 5 2016 $
+.Dd $Mdocdate: March 12 2016 $
 .Dt MALLOC 3
 .Os
 .Sh NAME
@@ -173,10 +173,6 @@ and set
 .Va errno
 to
 .Er ENOMEM .
-.Pp
-The
-.Fn free
-function returns no value.
 .Sh IDIOMS
 Consider
 .Fn calloc

src/lib/libc/stdlib/qsort.3

@@ -29,9 +29,9 @@
 .\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 .\" SUCH DAMAGE.
 .\"
-.\"	$OpenBSD: qsort.3,v 1.18 2015/01/29 01:46:31 schwarze Exp $
+.\"	$OpenBSD: qsort.3,v 1.19 2016/03/12 21:31:22 mmcc Exp $
 .\"
-.Dd $Mdocdate: January 29 2015 $
+.Dd $Mdocdate: March 12 2016 $
 .Dt QSORT 3
 .Os
 .Sh NAME
@@ -143,10 +143,6 @@ which is faster than
 .Fn heapsort .
 Memory availability and pre-existing order in the data can make this untrue.
 .Sh RETURN VALUES
-The
-.Fn qsort
-function returns no value.
-.Pp
 .Rv -std heapsort mergesort
 .Sh ERRORS
 The

src/lib/libc/stdlib/tsearch.3

@@ -1,4 +1,4 @@
-.\" $OpenBSD: tsearch.3,v 1.19 2013/06/05 03:39:23 tedu Exp $
+.\" $OpenBSD: tsearch.3,v 1.20 2016/03/12 21:31:22 mmcc Exp $
 .\"
 .\" Copyright (c) 1997 Todd C. Miller <Todd.Miller@courtesan.com>
 .\"
@@ -14,7 +14,7 @@
 .\" ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
 .\" OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 .\"
-.Dd $Mdocdate: June 5 2013 $
+.Dd $Mdocdate: March 12 2016 $
 .Dt TSEARCH 3
 .Os
 .Sh NAME
@@ -111,10 +111,6 @@ if
 is
 .Dv NULL
 or the datum cannot be found.
-.Pp
-The
-.Fn twalk
-function returns no value.
 .Sh SEE ALSO
 .Xr bsearch 3 ,
 .Xr lsearch 3