udhcp: MAC_BCAST_ADDR and blank_chaddr are in fact constant, move to rodata.

a few global variables reduced to smallints
function                                             old     new   delta
add_lease                                             75     227    +152
static.blank_chaddr                                    -      16     +16
MAC_BCAST_ADDR                                         -       6      +6
sockfd                                                 4       8      +4
udhcp_run_script                                    1153    1155      +2
state                                                  8       5      -3
listen_mode                                            4       1      -3
perform_release                                      152     148      -4
fd                                                     8       4      -4
blank_chaddr                                          16       -     -16
udhcpc_main                                         2518    2497     -21
.rodata                                           131864  131832     -32
oldest_expired_lease                                  61       -     -61
clear_lease                                          127       -    -127
------------------------------------------------------------------------------
(add/remove: 2/3 grow/shrink: 3/6 up/down: 180/-271)          Total: -91 bytes

1 files changed, 1 insertions, 1 deletions

diff --git a/networking/udhcp/serverpacket.c b/networking/udhcp/serverpacket.c
index 8889fda86..e1a88addd 100644
--- a/networking/udhcp/serverpacket.c
+++ b/networking/udhcp/serverpacket.c
@@ -38,7 +38,7 @@ static int send_packet_to_relay(struct dhcpMessage *payload)
 /* send a packet to a specific arp address and ip address by creating our own ip packet */
 static int send_packet_to_client(struct dhcpMessage *payload, int force_broadcast)
 {
-        uint8_t *chaddr;
+        const uint8_t *chaddr;
         uint32_t ciaddr;
 
         if (force_broadcast) {