kconfig: use bool instead of boolean for type definition attributes

Support for keyword 'boolean' will be dropped later on.

No functional change.

Reference: http://lkml.kernel.org/r/cover.1418003065.git.cj@linux.com
Signed-off-by: Christoph Jaeger <cj@linux.com>
Signed-off-by: Michal Marek <mmarek@suse.cz>
diff --git a/drivers/md/Kconfig b/drivers/md/Kconfig
index 5bdedf6..1cd9cf8 100644
--- a/drivers/md/Kconfig
+++ b/drivers/md/Kconfig
@@ -177,7 +177,7 @@
 source "drivers/md/bcache/Kconfig"
 
 config BLK_DEV_DM_BUILTIN
-	boolean
+	bool
 
 config BLK_DEV_DM
 	tristate "Device mapper support"
@@ -196,7 +196,7 @@
 	  If unsure, say N.
 
 config DM_DEBUG
-	boolean "Device mapper debugging support"
+	bool "Device mapper debugging support"
 	depends on BLK_DEV_DM
 	---help---
 	  Enable this for messages that may help debug device-mapper problems.