ip/iptunnel: Fix incorrect syntax in man page

Reported-by: Andreas Henriksson <andreas@fatal.se>
Signed-off-by: David Ward <david.ward@ll.mit.edu>

man/man8/ip-tunnel.8

@@ -60,9 +60,9 @@ ip-tunnel - tunnel configuration
 .IR TOS " := { " STRING " | " 00 ".." ff " |"
 .BR inherit " |"
 .BI "inherit/" STRING
-.R " |"
+.RB "|"
 .BI "inherit/" 00 ".." ff
-.R " }"
+.RB "}"
 
 .ti -8
 .IR ELIM " := {"