Use void instead of no parameters in 2 function declarations.

In compiling some code with a picky "Android.mk" file, it is not happy
with a function declaration that looks like:

    void foo();

It requires:

    void foo(void);

This commit changes that for 2 functions in "log.h".

Test: Build both Android and the code with a picky "Android.mk".
Change-Id: Icd624df34db57e642fe6b1c7da77be9b05936936