UBIFS: simplify UBIFS Kconfig menu

Remove debug message level and debug checks Kconfig options as they
proved to be useless anyway. We have sysfs interface which we can
use for fine-grained debugging messages and checks selection, see
Documentation/filesystems/ubifs.txt for mode details.

Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>

fs/ubifs/Kconfig

@@ -44,23 +44,20 @@ config UBIFS_FS_ZLIB
 
 # Debugging-related stuff
 config UBIFS_FS_DEBUG
-	bool "Enable debugging"
+	bool "Enable debugging support"
 	depends on UBIFS_FS
 	select DEBUG_FS
 	select KALLSYMS_ALL
 	help
-	  This option enables UBIFS debugging.
-
-config UBIFS_FS_DEBUG_MSG_LVL
-	int "Default message level (0 = no extra messages, 3 = lots)"
-	depends on UBIFS_FS_DEBUG
-	default "0"
-	help
-	  This controls the amount of debugging messages produced by UBIFS.
-	  If reporting bugs, please try to have available a full dump of the
-	  messages at level 1 while the misbehaviour was occurring. Level 2
-	  may become necessary if level 1 messages were not enough to find the
-	  bug. Generally Level 3 should be avoided.
+	  This option enables UBIFS debugging support. It makes sure various
+	  assertions, self-checks, debugging messages and test modes are compiled
+	  in (this all is compiled out otherwise). Assertions are light-weight
+	  and this option also enables them. Self-checks, debugging messages and
+	  test modes are switched off by default. Thus, it is safe and actually
+	  recommended to have debugging support enabled, and it should not slow
+	  down UBIFS. You can then further enable / disable individual  debugging
+	  features using UBIFS module parameters and the corresponding sysfs
+	  interfaces.
 
 config UBIFS_FS_DEBUG_CHKS
 	bool "Enable extra checks"