bootutil: trivial fixes

Signed-off-by: Marti Bolivar <marti.bolivar@linaro.org>
diff --git a/boot/bootutil/include/bootutil/bootutil.h b/boot/bootutil/include/bootutil/bootutil.h
index c349548..5f65866 100644
--- a/boot/bootutil/include/bootutil/bootutil.h
+++ b/boot/bootutil/include/bootutil/bootutil.h
@@ -6,7 +6,7 @@
  * to you under the Apache License, Version 2.0 (the
  * "License"); you may not use this file except in compliance
  * with the License.  You may obtain a copy of the License at
- * 
+ *
  *  http://www.apache.org/licenses/LICENSE-2.0
  *
  * Unless required by applicable law or agreed to in writing,
@@ -32,7 +32,7 @@
 /** Swap to slot 1.  Absent a confirm command, revert back on next boot. */
 #define BOOT_SWAP_TYPE_TEST     2
 
-/** Swap to slot 1 permanently. */
+/** Swap to slot 1, and permanently switch to booting its contents. */
 #define BOOT_SWAP_TYPE_PERM     3
 
 /** Swap back to alternate slot.  A confirm changes this state to NONE. */