[all] use explicit void parameter lists

This makes it a compile-time error to call a function that semantically
takes no parameters with a nonzero number of arguments.

Previously, such code would still compile, but risk blowing up the stack
if a compiler chose to use something other than caller-cleanup calling
conventions.

profile/client/src/main.c

@@ -104,7 +104,7 @@ static bool config_load(int argc, char * argv[])
   return true;
 }
 
-static int run()
+static int run(void)
 {
   PLGMPClient      lgmp;
   PLGMPClientQueue frameQueue;