env: Adjust the load() method to return an error

The load() methods have inconsistent behaviour on error. Some of them load
an empty default environment. Some load an environment containing an error
message. Others do nothing.

As a step in the right direction, have the method return an error code.
Then the caller could handle this itself in a consistent way.

Signed-off-by: Simon Glass <sjg@chromium.org>
diff --git a/env/sf.c b/env/sf.c
index 07386c6..6f74371 100644
--- a/env/sf.c
+++ b/env/sf.c
@@ -61,7 +61,7 @@
 				     0, 0, &new);
 	if (ret) {
 		set_default_env("!spi_flash_probe_bus_cs() failed");
-		return 1;
+		return ret;
 	}
 
 	env_flash = dev_get_uclass_priv(new);
@@ -73,7 +73,7 @@
 			CONFIG_ENV_SPI_MAX_HZ, CONFIG_ENV_SPI_MODE);
 		if (!env_flash) {
 			set_default_env("!spi_flash_probe() failed");
-			return 1;
+			return -EIO;
 		}
 	}
 #endif
@@ -95,7 +95,7 @@
 
 	ret = env_export(&env_new);
 	if (ret)
-		return ret;
+		return -EIO;
 	env_new.flags	= ACTIVE_FLAG;
 
 	if (gd->env_valid == ENV_VALID) {
@@ -112,7 +112,7 @@
 		saved_offset = env_new_offset + CONFIG_ENV_SIZE;
 		saved_buffer = memalign(ARCH_DMA_MINALIGN, saved_size);
 		if (!saved_buffer) {
-			ret = 1;
+			ret = -ENOMEM;
 			goto done;
 		}
 		ret = spi_flash_read(env_flash, saved_offset,
@@ -162,7 +162,7 @@
 }
 #endif /* CMD_SAVEENV */
 
-static void env_sf_load(void)
+static int env_sf_load(void)
 {
 	int ret;
 	int crc1_ok = 0, crc2_ok = 0;
@@ -176,6 +176,7 @@
 			CONFIG_ENV_SIZE);
 	if (!tmp_env1 || !tmp_env2) {
 		set_default_env("!malloc() failed");
+		ret = -EIO;
 		goto out;
 	}
 
@@ -202,6 +203,7 @@
 
 	if (!crc1_ok && !crc2_ok) {
 		set_default_env("!bad CRC");
+		ret = -EIO;
 		goto err_read;
 	} else if (crc1_ok && !crc2_ok) {
 		gd->env_valid = ENV_VALID;
@@ -244,6 +246,8 @@
 out:
 	free(tmp_env1);
 	free(tmp_env2);
+
+	return ret;
 }
 #else
 #ifdef CMD_SAVEENV
@@ -308,7 +312,7 @@
 }
 #endif /* CMD_SAVEENV */
 
-static void env_sf_load(void)
+static int env_sf_load(void)
 {
 	int ret;
 	char *buf = NULL;
@@ -316,7 +320,7 @@
 	buf = (char *)memalign(ARCH_DMA_MINALIGN, CONFIG_ENV_SIZE);
 	if (!buf) {
 		set_default_env("!malloc() failed");
-		return;
+		return -EIO;
 	}
 
 	ret = setup_flash_device();
@@ -339,6 +343,8 @@
 	env_flash = NULL;
 out:
 	free(buf);
+
+	return ret;
 }
 #endif