spl: Drop a duplicate variable in boot_from_devices()

The variable 'ret' is defined twice, which is not intended. This may
have been a local merge error.

Signed-off-by: Simon Glass <sjg@chromium.org>
Fixes: 2eefeb6d893 ("spl: Report a loader failure")

common/spl/spl.c

@@ -612,7 +612,6 @@ static int boot_from_devices(struct spl_image_info *spl_image,
 	for (i = 0; i < count && spl_boot_list[i] != BOOT_DEVICE_NONE; i++) {
 		struct spl_image_loader *loader;
 		int bootdev = spl_boot_list[i];
-		int ret;
 
 		if (CONFIG_IS_ENABLED(SHOW_ERRORS))
 			ret = -ENXIO;