Main fixes:

* Use int32_t replace int, use uint32_t replace unsign int
  [Rule 4.6]
* Add function define to header file [Rule 8.4]
* Added curly braces ({}) around if statements in order to
  make them compound [Rule 15.6]
* Voided non c-library functions whose return types are not used
  [Rule 17.7]

Change-Id: Ifa3ba4e75046697cfede885096bee9a30efe6519
Signed-off-by: Anthony Zhou <anzhou@nvidia.com>