CLEANUP: mux-h1/mux-pt: Remove useless test on SE_FL_SHR/SE_FL_SHW flags

It is already performed by the called, sc_conn_shutr() and
sc_conn_shutw(). So there is no reason to still test these flags in the PT
and H1 muxes.
diff --git a/src/mux_h1.c b/src/mux_h1.c
index f6d385b..1292661 100644
--- a/src/mux_h1.c
+++ b/src/mux_h1.c
@@ -3550,8 +3550,6 @@
 
 	TRACE_ENTER(H1_EV_STRM_SHUT, h1c->conn, h1s, 0, (size_t[]){mode});
 
-	if (se_fl_test(h1s->sd, SE_FL_SHW))
-		goto end;
 	if (se_fl_test(h1s->sd, SE_FL_KILL_CONN)) {
 		TRACE_STATE("stream wants to kill the connection", H1_EV_STRM_SHUT, h1c->conn, h1s);
 		goto do_shutw;
diff --git a/src/mux_pt.c b/src/mux_pt.c
index f7a7292..6f83ae4 100644
--- a/src/mux_pt.c
+++ b/src/mux_pt.c
@@ -466,8 +466,6 @@
 
 	TRACE_ENTER(PT_EV_STRM_SHUT, conn, sc);
 
-	if (se_fl_test(ctx->sd, SE_FL_SHR))
-		return;
 	se_fl_clr(ctx->sd, SE_FL_RCV_MORE | SE_FL_WANT_ROOM);
 	if (conn_xprt_ready(conn) && conn->xprt->shutr)
 		conn->xprt->shutr(conn, conn->xprt_ctx,
@@ -487,8 +485,6 @@
 
 	TRACE_ENTER(PT_EV_STRM_SHUT, conn, sc);
 
-	if (se_fl_test(ctx->sd, SE_FL_SHW))
-		return;
 	if (conn_xprt_ready(conn) && conn->xprt->shutw)
 		conn->xprt->shutw(conn, conn->xprt_ctx,
 		    (mode == CO_SHW_NORMAL));