vfree can handle NULL pointer as its argument.
According to coccinelle isnullfree check, remove NULL check
before vfree operation.
Signed-off-by: Dongliang Mu <mudongliangabcd@gmail.com>
Link: https://lore.kernel.org/r/20220614133239.147076-1-dzm91@hust.edu.cnSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>