Use .Er macro when referring to errno error names.

src/lib/libc/stdlib/strtod.3

@@ -33,7 +33,7 @@
 .\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 .\" SUCH DAMAGE.
 .\"
-.\"	$OpenBSD: strtod.3,v 1.4 1999/06/29 18:36:23 aaron Exp $
+.\"	$OpenBSD: strtod.3,v 1.5 2000/01/22 12:05:49 aaron Exp $
 .\"
 .Dd June 29, 1991
 .Dt STRTOD 3
@@ -87,12 +87,12 @@ is stored in the location referenced by
 If the correct value would cause overflow, plus or minus
 .Dv HUGE_VAL
 is returned (according to the sign of the value), and
-.Dv ERANGE
+.Er ERANGE
 is stored in
 .Va errno .
 If the correct value would cause underflow, zero is
 returned and
-.Dv ERANGE
+.Er ERANGE
 is stored in
 .Va errno .
 .Sh ERRORS