Fix wrong error message count in QDBusError

Don't pass the pointer errorMessages_string - 1 to strcmp().

-1 marks the end should not be used for the pointer arithmetic
in get(const char *name)

Change-Id: I5ec239c63f074d104d441511294554f21fd6eccd
Reviewed-by: Thiago Macieira <thiago.macieira@intel.com>

src/dbus/qdbuserror.cpp

@@ -142,7 +142,7 @@ static const int errorMessages_indices[] = {
 };
 
 static const int errorMessages_count = sizeof errorMessages_indices /
-                                       sizeof errorMessages_indices[0];
+                                       sizeof errorMessages_indices[0] - 1;
 
 static inline const char *get(QDBusError::ErrorType code)
 {