BUG/MINOR: mux-h1: Use the right variable to set NEGO_FF_FL_EXACT_SIZE flag

Instead of setting this flag on the ones used for the zero-copy negociation,
it is set on the connection flags used for xprt->rcv_buf()
call. Fortunately, there is no real consequence. The only visible effect is
the chunk size that is written on 8 bytes for no reason.

This patch is related to issue #2598. It must be backported to 3.0.

(cherry picked from commit 7bff576)
Signed-off-by: Christopher Faulet <[email protected]>

Author: capflam

src/mux_h1.c

@@ -4862,7 +4862,7 @@ static int h1_fastfwd(struct stconn *sc, unsigned int count, unsigned int flags)
 	ret = 0;
 
 	if (h1m->state == H1_MSG_DATA && (h1m->flags & (H1_MF_CHNK|H1_MF_CLEN)) &&  count > h1m->curr_len) {
-		flags |= NEGO_FF_FL_EXACT_SIZE;
+		nego_flags |= NEGO_FF_FL_EXACT_SIZE;
 		count = h1m->curr_len;
 	}