CLEANUP: fix all duplicated semicolons

trivial commit, does not change the code behaviour

Signed-off-by: William Dauchy <w.dauchy@criteo.com>
diff --git a/src/mux_fcgi.c b/src/mux_fcgi.c
index 8750498..ab9ddf0 100644
--- a/src/mux_fcgi.c
+++ b/src/mux_fcgi.c
@@ -825,7 +825,7 @@
  */
 static void fcgi_release(struct fcgi_conn *fconn)
 {
-	struct connection *conn = NULL;;
+	struct connection *conn = NULL;
 
 	TRACE_POINT(FCGI_EV_FCONN_END);
 
diff --git a/src/mux_h2.c b/src/mux_h2.c
index 44955ba..bfa65bd 100644
--- a/src/mux_h2.c
+++ b/src/mux_h2.c
@@ -926,7 +926,7 @@
  */
 static void h2_release(struct h2c *h2c)
 {
-	struct connection *conn = NULL;;
+	struct connection *conn = NULL;
 
 	TRACE_ENTER(H2_EV_H2C_END);
 
diff --git a/src/ring.c b/src/ring.c
index 7c7d58e..2ee6c10 100644
--- a/src/ring.c
+++ b/src/ring.c
@@ -186,7 +186,7 @@
 		totlen += len;
 	}
 
-	*b_tail(buf) = 0; buf->data++;; // new read counter
+	*b_tail(buf) = 0; buf->data++; // new read counter
 	sent = lenlen + totlen + 1;
 
 	/* notify potential readers */