[CLEANUP] session: remove data_source from struct session

This one was only used for logging purposes, it's not needed
anymore.
diff --git a/include/types/proto_http.h b/include/types/proto_http.h
index 1fdaf0f..cdd0a61 100644
--- a/include/types/proto_http.h
+++ b/include/types/proto_http.h
@@ -186,10 +186,6 @@
 #define HTTP_MSG_CLOSED       35 // shutdown_w done, all bytes sent
 #define HTTP_MSG_TUNNEL       36 // tunneled data after DONE
 
-/* various data sources for the responses */
-#define DATA_SRC_NONE	0
-#define DATA_SRC_STATS	1
-
 /* data transmission states for the stats responses */
 enum {
 	DATA_ST_INIT = 0,
diff --git a/include/types/session.h b/include/types/session.h
index 25ddcd5..019eea2 100644
--- a/include/types/session.h
+++ b/include/types/session.h
@@ -203,7 +203,6 @@
 	void (*do_log)(struct session *s);	/* the function to call in order to log (or NULL) */
 	void (*srv_error)(struct session *s,	/* the function to call upon unrecoverable server errors (or NULL) */
 			  struct stream_interface *si);
-	short int data_source;			/* where to get the data we generate ourselves */
 	short int data_state;			/* where to get the data we generate ourselves */
 	union {
 		struct {
diff --git a/src/dumpstats.c b/src/dumpstats.c
index f434cdf..8e3ded2 100644
--- a/src/dumpstats.c
+++ b/src/dumpstats.c
@@ -99,7 +99,6 @@
 	s->logs.srv_queue_size = 0; /* we will get this number soon */
 
 	s->data_state = DATA_ST_INIT;
-	s->data_source = DATA_SRC_NONE;
 
 	s->req->flags |= BF_READ_DONTWAIT; /* we plan to read small requests */
 
@@ -863,7 +862,6 @@
 		if (si->applet.st0 == STAT_CLI_INIT) {
 			/* Stats output not initialized yet */
 			memset(&s->data_ctx.stats, 0, sizeof(s->data_ctx.stats));
-			s->data_source = DATA_SRC_STATS;
 			si->applet.st0 = STAT_CLI_GETREQ;
 		}
 		else if (si->applet.st0 == STAT_CLI_END) {
diff --git a/src/frontend.c b/src/frontend.c
index 6e8e1a4..f818a96 100644
--- a/src/frontend.c
+++ b/src/frontend.c
@@ -76,7 +76,6 @@
 	s->logs.srv_queue_size = 0; /* we will get this number soon */
 
 	s->data_state  = DATA_ST_INIT;
-	s->data_source = DATA_SRC_NONE;
 
 	/* FIXME: the logs are horribly complicated now, because they are
 	 * defined in <p>, <p>, and later <be> and <be>.
diff --git a/src/peers.c b/src/peers.c
index dd74ec3..78855a1 100644
--- a/src/peers.c
+++ b/src/peers.c
@@ -1204,8 +1204,6 @@
 	/* default error reporting function, may be changed by analysers */
 	s->srv_error = default_srv_error;
 
-	s->data_source = DATA_SRC_NONE;
-
 	s->uniq_id = 0;
 
 	txn = &s->txn;
diff --git a/src/proto_http.c b/src/proto_http.c
index 7830580..75eb508 100644
--- a/src/proto_http.c
+++ b/src/proto_http.c
@@ -3243,7 +3243,6 @@
 		}
 
 		s->logs.tv_request = now;
-		s->data_source = DATA_SRC_STATS;
 		s->data_state  = DATA_ST_INIT;
 		s->task->nice = -32; /* small boost for HTTP statistics */
 		stream_int_register_handler(s->rep->prod, &http_stats_applet);