qemu-doc: Fix ivshmem example markup

Use @var{foo} like we do everywhere else, not <foo>.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <1448384789-14830-2-git-send-email-armbru@redhat.com>
Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com>

qemu-doc.texi

@@ -1256,7 +1256,7 @@ zero-copy communication to the application level of the guests.  The basic
 syntax is:
 
 @example
-qemu-system-i386 -device ivshmem,size=<size in format accepted by -m>[,shm=<shm name>]
+qemu-system-i386 -device ivshmem,size=@var{size}[,shm=@var{shm-name}]
 @end example
 
 If desired, interrupts can be sent between guest VMs accessing the same shared
@@ -1267,12 +1267,12 @@ memory server is:
 
 @example
 # First start the ivshmem server once and for all
-ivshmem-server -p <pidfile> -S <path> -m <shm name> -l <shm size> -n <vectors n>
+ivshmem-server -p @var{pidfile} -S @var{path} -m @var{shm-name} -l @var{shm-size} -n @var{vectors}
 
 # Then start your qemu instances with matching arguments
-qemu-system-i386 -device ivshmem,size=<shm size>,vectors=<vectors n>,chardev=<id>
+qemu-system-i386 -device ivshmem,size=@var{shm-size},vectors=@var{vectors},chardev=@var{id}
                  [,msi=on][,ioeventfd=on][,role=peer|master]
-                 -chardev socket,path=<path>,id=<id>
+                 -chardev socket,path=@var{path},id=@var{id}
 @end example
 
 When using the server, the guest will be assigned a VM ID (>=0) that allows guests