mctp-demux-daemon: Silence warnings on remote close

If applications constantly connect then disconnect from the demux daemon
we see a "flood" of messages like:

    Mar 05 07:15:47 w57 mctp-demux[177]: mctp-demux-daemon: can't receive(peek) from client: Connection reset by peer
    Mar 05 07:15:52 w57 mctp-demux[177]: mctp-demux-daemon: can't receive(peek) from client: Connection reset by peer
    Mar 05 07:15:52 w57 mctp-demux[177]: mctp-demux-daemon: can't receive(peek) from client: Connection reset by peer
    Mar 05 07:15:53 w57 mctp-demux[177]: mctp-demux-daemon: can't receive(peek) from client: Connection reset by peer
    Mar 05 07:15:54 w57 mctp-demux[177]: mctp-demux-daemon: can't receive(peek) from client: Connection reset by peer

Signed-off-by: Andrew Jeffery <andrew@aj.id.au>
Change-Id: I99eabffd45693e5ab570575c4c8cca2ee55196e0
diff --git a/utils/mctp-demux-daemon.c b/utils/mctp-demux-daemon.c
index d223279..b7500b5 100644
--- a/utils/mctp-demux-daemon.c
+++ b/utils/mctp-demux-daemon.c
@@ -4,6 +4,7 @@
 
 #include <assert.h>
 #include <err.h>
+#include <errno.h>
 #include <getopt.h>
 #include <poll.h>
 #include <stdbool.h>
@@ -326,7 +327,9 @@
 
 	len = recv(client->sock, NULL, 0, MSG_PEEK | MSG_TRUNC);
 	if (len < 0) {
-		warn("can't receive(peek) from client");
+		if (errno != ECONNRESET)
+			warn("can't receive (peek) from client");
+
 		rc = -1;
 		goto out_close;
 	}
@@ -346,7 +349,8 @@
 
 	rc = recv(client->sock, ctx->buf, ctx->buf_size, 0);
 	if (rc < 0) {
-		warn("can't receive from client");
+		if (errno != ECONNRESET)
+			warn("can't receive from client");
 		rc = -1;
 		goto out_close;
 	}