Manpages, cmdsynopsis and sbr

Hello!

I have found the following formatting error when using <sbr/> in 
cmdsynopsis, for manpages.

DocBook code:

<cmdsynopsis>
   <command>bdmond</command>
   <arg choice="opt">-s, --start</arg><sbr/>
   <arg choice="opt">-k, --stop</arg><sbr/>
   <arg choice="opt">-h, --help</arg><sbr/>
   <arg choice="opt">-V, --version</arg>
</cmdsynopsis>

The roff output is the following:

.SH "SYNOPSIS"
.ad l
.HP 7
\fBbdmond\fR [\-s,\ \-\-start]
.br
  [\-k,\ \-\-stop]
.br
  [\-h,\ \-\-help]
.br
  [\-V,\ \-\-version]
.ad

As you can see, in front of the '[' character from the arguments, at the 
beginning of the line, after the '.br' lines, there is an empty space. 
When processed, the text is this one:

SYNOPSIS
        bdmond [-s, --start]
                [-k, --stop]
                [-h, --help]
                [-V, --version]