Markup fixes. Document more correctly.

PR:		43678
Submitted by:	ru

usr.sbin/pciconf/pciconf.8

@@ -43,9 +43,13 @@
 The
 .Nm
 utility provides a command line interface to the functionality provided by
-.Pa /dev/pci Ns 's
+.Xr pci 4
 .Xr ioctl 2
 interface.
+As such, it is only available to users with write access to
+.Pa /dev/pci ,
+normally only super-user.
+.Pp
 With the
 .Fl l
 option, it lists all devices found by the boot probe in the following format:
@@ -70,7 +74,8 @@ If there is no device configured in the kernel for the
 device in question, the device name will be
 .Dq none .
 Unit numbers for unconfigured devices start at zero and are incremented for
-each unconfigured device that is encountered.  The
+each unconfigured device that is encountered.
+The
 .Ar selector
 is in a form which may directly be used for the other forms of the command.
 The second column is the class code, with the class byte printed as two
@@ -108,11 +113,10 @@ device, it is a
 device, which contains several (similar or independent) functions on
 one chip.
 .Pp
-The
-.Fl l
-option is the only one available to non-root users.
-All other invocations of
+All invocations of
 .Nm
+except for
+.Fl l
 require a
 .Ar selector
 of the form
@@ -123,7 +127,8 @@ A final colon may be appended and
 will be ignored; this is so that the first column in the output of
 .Nm
 .Fl l
-can be used without modification.  All numbers are base 10.
+can be used without modification.
+All numbers are base 10.
 .Pp
 With the
 .Fl a
@@ -161,7 +166,8 @@ select the width of the operation;
 .Fl b
 indicates a byte operation, and
 .Fl h
-indicates a halfword (two-byte) operation.  The default is to read or
+indicates a halfword (two-byte) operation.
+The default is to read or
 write a longword (four bytes).
 .Sh ENVIRONMENT
 The PCI vendor/device information database is normally read from