devtools: call common_setup in main

Fixes nullability errors detected by UBSan:

wire/fromwire.c:173:46: runtime error: null pointer passed as argument 1, which is declared to never be null
external/libwally-core/src/secp256k1/include/secp256k1.h:432:3: note: nonnull attribute specified here
    #0 0x65214a in fromwire_secp256k1_ecdsa_signature wire/fromwire.c:173:6
    #1 0x659500 in printwire_secp256k1_ecdsa_signature devtools/print_wire.c:331:1
    #2 0x646ba2 in printwire_channel_update wire/peer_printgen.c:1900:7
    #3 0x637182 in printpeer_wire_message wire/peer_printgen.c:128:11
    #4 0x65a097 in main devtools/decodemsg.c:85:10

Author: morehouse

devtools/decodemsg.c

@@ -1,3 +1,4 @@
+#include "common/setup.h"
 #include "config.h"
 #include <ccan/err/err.h>
 #include <ccan/opt/opt.h>
@@ -55,6 +56,7 @@ int main(int argc, char *argv[])
 	bool (*printwire)(const u8 *msg) = printpeer_wire_message;
 	bool ok = true;
 
+	common_setup(argv[0]);
 	setup_locale();
 
 	opt_register_noarg("--onion", opt_set_onionprint, &printwire,

devtools/route.c

@@ -1,3 +1,4 @@
+#include "common/setup.h"
 #include "config.h"
 #include <ccan/err/err.h>
 #include <ccan/opt/opt.h>
@@ -70,6 +71,8 @@ int main(int argc, char *argv[])
 	bool clean_topology = false;
 	size_t num_channel_updates_rejected;
 
+	common_setup(argv[0]);
+
 	opt_register_noarg("--clean-topology", opt_set_bool, &clean_topology,
 			   "Clean up topology before run");
 	opt_register_noarg("-h|--help", opt_usage_and_exit,