MIPS: BCM47XX: use common error codes in nvram reads

Instead of using our own error codes use some common codes.
Signed-off-by: NHauke Mehrtens <hauke@hauke-m.de>
Patchwork: http://patchwork.linux-mips.org/patch/4739/Signed-off-by: NJohn Crispin <blogic@openwrt.org>

arch/mips/bcm47xx/nvram.c

@@ -124,7 +124,7 @@ int nvram_getenv(char *name, char *val, size_t val_len)
 	char *var, *value, *end, *eq;
 
 	if (!name)
-		return NVRAM_ERR_INV_PARAM;
+		return -EINVAL;
 
 	if (!nvram_buf[0])
 		early_nvram_init();
@@ -143,6 +143,6 @@ int nvram_getenv(char *name, char *val, size_t val_len)
 			return snprintf(val, val_len, "%s", value);
 		}
 	}
-	return NVRAM_ERR_ENVNOTFOUND;
+	return -ENOENT;
 }
 EXPORT_SYMBOL(nvram_getenv);

arch/mips/bcm47xx/sprom.c

@@ -51,7 +51,7 @@ static int get_nvram_var(const char *prefix, const char *postfix,
 	create_key(prefix, postfix, name, key, sizeof(key));
 
 	err = nvram_getenv(key, buf, len);
-	if (fallback && err == NVRAM_ERR_ENVNOTFOUND && prefix) {
+	if (fallback && err == -ENOENT && prefix) {
 		create_key(NULL, postfix, name, key, sizeof(key));
 		err = nvram_getenv(key, buf, len);
 	}

arch/mips/include/asm/mach-bcm47xx/nvram.h

@@ -32,9 +32,6 @@ struct nvram_header {
 #define NVRAM_MAX_VALUE_LEN 255
 #define NVRAM_MAX_PARAM_LEN 64
 
-#define NVRAM_ERR_INV_PARAM	-8
-#define NVRAM_ERR_ENVNOTFOUND	-9
-
 extern int nvram_getenv(char *name, char *val, size_t val_len);
 
 static inline void nvram_parse_macaddr(char *buf, u8 macaddr[6])