net: ipv4: remove define INET_CSK_DEBUG and unnecessary EXPORT_SYMBOL

INET_CSK_DEBUG is always set and only is used for 2 pr_debug calls.

EXPORT_SYMBOL(inet_csk_timer_bug_msg) is only used by these 2
pr_debug calls and is also unnecessary as the exported string can
be used directly by these calls.

Signed-off-by: Joe Perches <[e-mail]>
Signed-off-by: David S. Miller <[e-mail]>

include/net/inet_connection_sock.h

···
 #include <net/inet_sock.h>
 #include <net/request_sock.h>
 
-#define INET_CSK_DEBUG 1
-
 /* Cancel timers, when they are not required. */
 #undef INET_CSK_CLEAR_TIMERS
 
···
 void inet_csk_delete_keepalive_timer(struct sock *sk);
 void inet_csk_reset_keepalive_timer(struct sock *sk, unsigned long timeout);
 
-#ifdef INET_CSK_DEBUG
-extern const char inet_csk_timer_bug_msg[];
-#endif
-
 static inline void inet_csk_clear_xmit_timer(struct sock *sk, const int what)
 {
 	struct inet_connection_sock *icsk = inet_csk(sk);
···
 #ifdef INET_CSK_CLEAR_TIMERS
 		sk_stop_timer(sk, &icsk->icsk_delack_timer);
 #endif
+	} else {
+		pr_debug("inet_csk BUG: unknown timer value\n");
 	}
-#ifdef INET_CSK_DEBUG
-	else {
-		pr_debug("%s", inet_csk_timer_bug_msg);
-	}
-#endif
 }
 
 /*
···
 	struct inet_connection_sock *icsk = inet_csk(sk);
 
 	if (when > max_when) {
-#ifdef INET_CSK_DEBUG
 		pr_debug("reset_xmit_timer: sk=%p %d when=0x%lx, caller=%p\n",
 			 sk, what, when, current_text_addr());
-#endif
 		when = max_when;
 	}
 
···
 		icsk->icsk_ack.pending |= ICSK_ACK_TIMER;
 		icsk->icsk_ack.timeout = jiffies + when;
 		sk_reset_timer(sk, &icsk->icsk_delack_timer, icsk->icsk_ack.timeout);
+	} else {
+		pr_debug("inet_csk BUG: unknown timer value\n");
 	}
-#ifdef INET_CSK_DEBUG
-	else {
-		pr_debug("%s", inet_csk_timer_bug_msg);
-	}
-#endif
 }
 
 static inline unsigned long

net/ipv4/inet_connection_sock.c

···
 #include <net/sock_reuseport.h>
 #include <net/addrconf.h>
 
-#ifdef INET_CSK_DEBUG
-const char inet_csk_timer_bug_msg[] = "inet_csk BUG: unknown timer value\n";
-EXPORT_SYMBOL(inet_csk_timer_bug_msg);
-#endif
-
 #if IS_ENABLED(CONFIG_IPV6)
 /* match_wildcard == true:  IPV6_ADDR_ANY equals to any IPv6 addresses if IPv6
  *                          only, and any IPv4 addresses if not IPv6 only