manager: typo fix available

Typo fix in manager_cpp for word "available"

Change-Id: I0c4382023fef63f332d4cd677d82ad30e0a44b26
Signed-off-by: Patrick Venture <venture@google.com>
diff --git a/manager.cpp b/manager.cpp
index adabe84..bc96b34 100644
--- a/manager.cpp
+++ b/manager.cpp
@@ -115,7 +115,7 @@
         return false;
     }
 
-    /* No sessions availabe... */
+    /* No sessions available... */
     if (!getSession(session))
     {
         return false;