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/net/switchdev/Kconfig b/net/switchdev/Kconfig
index 1557545..86a47e1 100644
--- a/net/switchdev/Kconfig
+++ b/net/switchdev/Kconfig
@@ -3,7 +3,7 @@
 #
 
 config NET_SWITCHDEV
-	boolean "Switch (and switch-ish) device support (EXPERIMENTAL)"
+	bool "Switch (and switch-ish) device support (EXPERIMENTAL)"
 	depends on INET
 	---help---
 	  This module provides glue between core networking code and device