Staging: bcm: Change conditions that check for NULL in nvm.c

This patch changes all conditions that check for NULL
from "if (variable == NULL)" or "if (NULL == variable)"
to "if (variable)" to make code more readable.

Signed-off-by: Kevin McKinney <klmckinney1@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>