MIPS: lantiq: fix cmdline parsing

The code tested if the KSEG1 mapped address of argv was != 0. We need to use
CPHYSADDR instead to make the conditional actually work.
Signed-off-by: Thomas Langer <thomas.langer@lantiq.com>
Signed-off-by: John Crispin <blogic@openwrt.org>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/3722/Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

arch/mips/lantiq/prom.c

@@ -45,10 +45,12 @@ static void __init prom_init_cmdline(void)
 	char **argv = (char **) KSEG1ADDR(fw_arg1);
 	int i;
 
+	arcs_cmdline[0] = '\0';
+
 	for (i = 0; i < argc; i++) {
 		char *p = (char *) KSEG1ADDR(argv[i]);
 
-		if (p && *p) {
+		if (CPHYSADDR(p) && *p) {
 			strlcat(arcs_cmdline, p, sizeof(arcs_cmdline));
 			strlcat(arcs_cmdline, " ", sizeof(arcs_cmdline));
 		}