[Balloon] Changes to yaffs path-ker.sh script

Ballooners

I recently changed the patch-ker.sh script to support multi-version and
single-version variants of the yaffs VFS glue code.

The new form for the arguments is:

./patch-ker.sh c m /linux-dir

the old form was

./patch-ker.sh c /linux-dir


I now realise that this impacts on the balloon scripts.

There seem to be two options here:
1) I change patch-ker.sh script back and introduce another script for handling
the single-version patching.
2) The balloon script changes to the following logic:

if yaffs_vfs_multi.c exists 
    then
        ./patch-ker.sh c m /linux-dir
    else
        ./patch-ker.sh c /linux-dir

For me the second mechanism is a bit easier. It that an acceptable approach?

If so, I'll make a fix.

-- CHarles