make the strings for tcptimers, tanames and prurequests const to silence

warnings.

sys/netinet/tcp_debug.h

@@ -68,7 +68,7 @@ struct	tcp_debug {
 #define	TA_DROP		4
 
 #ifdef TANAMES
-static char	*tanames[] =
+static const char	*tanames[] =
     { "input", "output", "user", "respond", "drop" };
 #endif
 

sys/netinet/tcp_timer.h

@@ -123,7 +123,7 @@
 #define	TCPTV_DELACK	(hz / PR_FASTHZ / 2)	/* 100ms timeout */
 
 #ifdef	TCPTIMERS
-static char *tcptimers[] =
+static const char *tcptimers[] =
     { "REXMT", "PERSIST", "KEEP", "2MSL" };
 #endif
 

sys/sys/protosw.h

@@ -171,7 +171,7 @@ struct protosw {
 #define PRU_NREQ		22
 
 #ifdef PRUREQUESTS
-char *prurequests[] = {
+const char *prurequests[] = {
 	"ATTACH",	"DETACH",	"BIND",		"LISTEN",
 	"CONNECT",	"ACCEPT",	"DISCONNECT",	"SHUTDOWN",
 	"RCVD",		"SEND",		"ABORT",	"CONTROL",