From: Manuel Estrada Sainz <ranty@ranty.pantax.net>

Based on patch and suggestions from Dmitry Torokhov

- Take advantage of strlcpy.

- Extra error logging.

- Use struct coping instead of memcpy.

- Put all aborting code in a single place, and fully abort if
  fw_realloc_buffer fails.

- Abort on unexpected 'loading' values.