env: Use tabs in ENV_IS_IN_FAT

Tidy up the formatting of this option.

Signed-off-by: Simon Glass <sjg@chromium.org>
diff --git a/env/Kconfig b/env/Kconfig
index 9f97f9c..c8dd65f 100644
--- a/env/Kconfig
+++ b/env/Kconfig
@@ -81,11 +81,10 @@
 	depends on !CHAIN_OF_TRUST
 	select FAT_WRITE
 	help
-         Define this if you want to use the FAT file system for the environment.
-
+	  Define this if you want to use the FAT file system for the environment.
 
-         - CONFIG_FAT_WRITE:
-         This must be enabled. Otherwise it cannot save the environment file.
+	  - CONFIG_FAT_WRITE:
+	  This must be enabled. Otherwise it cannot save the environment file.
 
 config ENV_IS_IN_FLASH
 	bool "Environment in flash memory"