Input: adxl34x - fix leak and use after free

These are a couple smatch issues.  In the original code, if only one of
the allocation fails we leak the other variable so we should goto
out_free_mem.

Also there was a use after free if debugging was enabled and so I moved
the kfree() down a line.

Signed-off-by: Dan Carpenter <error27@gmail.com>
Signed-off-by: Dmitry Torokhov <dtor@mail.ru>