coding guidelines 11.9: fix literal zero as the null-ptr-constant

File has next violations:
MISRA 11_9_a
Use NULL instead of literal zero (0) as the null-pointer-constant
MISRA 11_9_b
Literal zero (0) shall not be used as the null-pointer-constant

Signed-off-by: Maksim Masalski <maksim.masalski@intel.com>