CLEANUP: muxes: Remove useless if condition in show_fd function

In H1, H2 and FCGI muxes, in the show_fd function, there is duplicated test on
the stream's subs field.

This patch fixes the issue #1142. It may be backported as far as 2.2.

(cherry picked from commit 6c93c4ef089fc79ce4e85fa0d9e7f61720291dba)
Signed-off-by: Christopher Faulet <cfaulet@haproxy.com>
diff --git a/src/mux_fcgi.c b/src/mux_fcgi.c
index 9efb96c..a8528e8 100644
--- a/src/mux_fcgi.c
+++ b/src/mux_fcgi.c
@@ -4104,14 +4104,12 @@
 				      fstrm->cs->flags, fstrm->cs->data);
 		chunk_appendf(&trash, " .subs=%p", fstrm->subs);
 		if (fstrm->subs) {
-			if (fstrm->subs) {
-				chunk_appendf(&trash, "(ev=%d tl=%p", fstrm->subs->events, fstrm->subs->tasklet);
-				chunk_appendf(&trash, " tl.calls=%d tl.ctx=%p tl.fct=",
-					      fstrm->subs->tasklet->calls,
-					      fstrm->subs->tasklet->context);
-				resolve_sym_name(&trash, NULL, fstrm->subs->tasklet->process);
-				chunk_appendf(&trash, ")");
-			}
+			chunk_appendf(&trash, "(ev=%d tl=%p", fstrm->subs->events, fstrm->subs->tasklet);
+			chunk_appendf(&trash, " tl.calls=%d tl.ctx=%p tl.fct=",
+				      fstrm->subs->tasklet->calls,
+				      fstrm->subs->tasklet->context);
+			resolve_sym_name(&trash, NULL, fstrm->subs->tasklet->process);
+			chunk_appendf(&trash, ")");
 		}
 	}
 	return 0;