Input: hideep - fix the uninitialized use in hideep_nvm_unlock()

Inside function hideep_nvm_unlock(), variable "unmask_code" could
be uninitialized if hideep_pgm_r_reg() returns error, however, it
is used in the later if statement after an "and" operation, which
is potentially unsafe.

Signed-off-by: Yizhuo <yzhai003@ucr.edu>
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>