Fix arguments

Signed-off-by: Sebastian Ramacher <sebastian+dev@ramacher.at>

girara/log.c

@@ -50,7 +50,7 @@ girara_log(const char* location, girara_log_level_t level, const char* format, .
 }
 
 girara_log_level_t
-girara_get_log_level()
+girara_get_log_level(void)
 {
   return log_level;
 }

girara/log.h

@@ -55,7 +55,7 @@ void girara_vlog(const char* location, girara_log_level_t level,
  * Get the log level.
  * @returns The log level.
  */
-girara_log_level_t girara_get_log_level();
+girara_log_level_t girara_get_log_level(void);
 
 /**
  * Set the log level. Any message with a level lower than the log level will