Merge pull request #2984 from Lotterleben/fib_fix_register_rrp

fib: rename register function in fib.c too

sys/net/network_layer/fib/fib.c

@@ -484,7 +484,7 @@ void fib_deinit(void)
     mutex_unlock(&mtx_access);
 }
 
-int fib_register_rrp(uint8_t *prefix, size_t prefix_size)
+int fib_register_rp(uint8_t *prefix, size_t prefix_size)
 {
     mutex_lock(&mtx_access);