USB: berry_charge: correct dbg string for second magic command

I was testing the berry_charge module with my Blackberry 8700c and had
great success, thanks. Looking at the code for my own learning I noticed
the following cut and paste error... just a nit.

Signed-off-by: Ken L Johnson <ken@novell.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>