bridge.8: minor formatting cleanup

- Replace commas at end of subsection with dots.
- Replace double whitespace by single one.
Signed-off-by: Phil Sutter <phil@nwl.cc>

man/man8/bridge.8

@@ -398,21 +398,21 @@ sends a copy of the data packet to each entry found.
 
 .PP
 The arguments are the same as with
-.BR "bridge fdb add" ,
+.BR "bridge fdb add" .
 
 .SS bridge fdb delete - delete a forwarding database entry
 This command removes an existing fdb entry.
 
 .PP
 The arguments are the same as with
-.BR "bridge fdb add" ,
+.BR "bridge fdb add" .
 
 .SS bridge fdb replace - replace a forwarding database entry
 If no matching entry is found, a new one will be created instead.
 
 .PP
 The arguments are the same as with
-.BR "bridge fdb add" ,
+.BR "bridge fdb add" .
 
 .SS bridge fdb show - list forwarding entries.