fir regression with VFS availability test on Windows

ensure we report the expected availability erro for non existing files

Signed-off-by: Matthieu Gallien <matthieu.gallien@nextcloud.com>

src/libsync/vfs/cfapi/vfs_cfapi.cpp

@@ -354,7 +354,7 @@ Vfs::AvailabilityResult VfsCfApi::availability(const QString &folderPath, const
             break;
         };
         return VfsItemAvailability::Mixed;
-    } else {
+    } else if (basePinState) {
         const auto hydrationAndPinStates = computeRecursiveHydrationAndPinStates(folderPath, basePinState);
 
         const auto pin = hydrationAndPinStates.pinState;
@@ -382,6 +382,8 @@ Vfs::AvailabilityResult VfsCfApi::availability(const QString &folderPath, const
             }
         }
         return AvailabilityError::NoSuchItem;
+    } else {
+        return AvailabilityError::NoSuchItem;
     }
 }