The function was using an anti-pattern where an argument is a static
length char array. Array arguments in C don't really exist but compilers
accept them and without any 'const' or 'static' decorators they don't
always emit a warning.

The proposed patch only fixes the unsafeness of the function
declaration but it does not address the usefulness of it.
Reviewed-by: NDaniel Gustafsson <dgustafsson@pivotal.io>