net: stmmac: fix return value of __setup handler

__setup() handlers should return 1 on success, i.e., the parameter
has been handled. A return of 0 causes the "option=value" string to be
added to init's environment strings, polluting it.

Fixes: 47dd7a5 ("net: add support for STMicroelectronics Ethernet controllers.")
Fixes: f3240e2 ("stmmac: remove warning when compile as built-in (V2)")
Signed-off-by: Randy Dunlap <[email protected]>
Reported-by: Igor Zhbanov <[email protected]>
Link: lore.kernel.org/r/[email protected]
Cc: Giuseppe Cavallaro <[email protected]>
Cc: Alexandre Torgue <[email protected]>
Cc: Jose Abreu <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Jakub Kicinski <[email protected]>

Author: rddunlap

drivers/net/ethernet/stmicro/stmmac/stmmac_main.c

@@ -7491,7 +7491,7 @@ static int __init stmmac_cmdline_opt(char *str)
 	char *opt;
 
 	if (!str || !*str)
-		return -EINVAL;
+		return 1;
 	while ((opt = strsep(&str, ",")) != NULL) {
 		if (!strncmp(opt, "debug:", 6)) {
 			if (kstrtoint(opt + 6, 0, &debug))
@@ -7522,11 +7522,11 @@ static int __init stmmac_cmdline_opt(char *str)
 				goto err;
 		}
 	}
-	return 0;
+	return 1;
 
 err:
 	pr_err("%s: ERROR broken module parameter conversion", __func__);
-	return -EINVAL;
+	return 1;
 }
 
 __setup("stmmaceth=", stmmac_cmdline_opt);