ppdev: don't print a free'd string

A previous fix of a memory leak now prints the string 'name'
that was previously free'd.  Fix this by free'ing the string
at the end of the function and adding an error exit path for
the error conditions.

CoverityScan CID#1384523 ("Use after free")

Fixes: 2bd362d5

 ("ppdev: fix memory leak")
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Acked-by: Sudip Mukherjee <sudipm.mukherjee@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>