Fix formatting of ip.8 family man page

fix bad formatting in description of -f option
diff --git a/man/man8/ip.8 b/man/man8/ip.8
index ede3d12..9ba3621 100644
--- a/man/man8/ip.8
+++ b/man/man8/ip.8
@@ -52,8 +52,8 @@
 followed by protocol family identifier:
 .BR "inet" , " inet6"
 or
-.B link
-,enforce the protocol family to use.  If the option is not present,
+.BR link ,
+enforce the protocol family to use.  If the option is not present,
 the protocol family is guessed from other arguments.  If the rest
 of the command line does not give enough information to guess the
 family,