The tg3 NVRAM selftest actually fails when validating the checksum of
the legacy NVRAM format.  However, the test still reported success
because the last update of the return code was a success from the NVRAM
reads.  This patch fixes the code so that the error return code defaults
to a failure status.  Then the patch fixes the reason why the checsum
validation failed.
Signed-off-by: Matt Carlson <mcarlson@broadcom.com>
Reviewed-by: Michael Chan <mchan@broadcom.com>
Signed-off-by: David S. Miller <davem@davemloft.net>