Groff cannot handle so many columns when using the proper syntax

involving .It, so we cannot use .Bl -column here and switch to .Bd.
Found by and unbreaking the build with mandoc(1).
While here, reduce the indentation, it looks better.
OK jmc@

1 files changed, 4 insertions, 6 deletions

diff --git a/share/man/man4/ahc.4 b/share/man/man4/ahc.4
index e91132eb553..a5ce78562d6 100644
--- a/share/man/man4/ahc.4
+++ b/share/man/man4/ahc.4
@@ -1,4 +1,4 @@
-.\"	$OpenBSD: ahc.4,v 1.36 2007/05/31 19:19:48 jmc Exp $
+.\"	$OpenBSD: ahc.4,v 1.37 2010/02/18 13:14:19 schwarze Exp $
 .\"	$NetBSD: ahc.4,v 1.1.2.1 1996/08/25 17:22:14 thorpej Exp $
 .\"
 .\" Copyright (c) 1995, 1996
@@ -27,7 +27,7 @@
 .\" THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 .\"
 .\"
-.Dd $Mdocdate: May 31 2007 $
+.Dd $Mdocdate: February 18 2010 $
 .Dt AHC 4
 .Os
 .Sh NAME
@@ -174,8 +174,7 @@ the
 driver.
 Note that wide and twin channel features, although always supported by a
 particular chip, may be disabled in a particular motherboard or card design.
-.Bd -ragged -offset indent
-.Bl -column "aic7770 " "10 " "EISA/VL  " "10MHz " "16bit " "SCBs " Features
+.Bd -literal
 .Em "Chip       MIPS    Bus      MaxSync   MaxWidth  SCBs  Features"
 aic7770     10    EISA/VL    10MHz     16Bit     4    1
 aic7850     10    PCI/32     10MHz      8Bit     3
@@ -190,7 +189,7 @@ aic7895C    15    PCI/32     20MHz     16Bit    16      2 3 4 5     8
 aic7896     20    PCI/32     40MHz     16Bit    16      2 3 4 5 6 7 8
 aic7897     20    PCI/64     40MHz     16Bit    16      2 3 4 5 6 7 8
 aic7899     20    PCI/64     80MHz     16Bit    16      2 3 4 5 6 7 8
-.El
+.Ed
 .Pp
 .Bl -enum -compact
 .It
@@ -217,7 +216,6 @@ Ultra160 support.
 Multiple Target IDs - Allows the controller to respond to selection as a target
 on multiple SCSI IDs.
 .El
-.Ed
 .Sh SCSI CONTROL BLOCKS (SCBs)
 Every transaction sent to a device on the SCSI bus is assigned a
 .Sq SCSI Control Block