staging: rtl8712: fix potential memory leak

staging: rtl8712: fix potential memory leak

In r8712_init_drv_sw(), whenever any function call returns error, it is
returned immediately without properly cleaning up the other successfully
executed functions. This can cause memory leak.

Instead of return immediately, free all the allocated buffers first.

Tested-by: Philipp Hortmann <philipp.g.hortmann@gmail.com>
Signed-off-by: Nam Cao <namcaov@gmail.com>
Link: https://lore.kernel.org/r/0a3414b12031f6cdcba81a8725e91eb9567ff34f.1666688642.git.namcaov@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>