OWNERS: fix syntax

The existing config is missing owners in exact match. Also, onwers have
to be array of strings.

Reference:
[1] https://gerrit.googlesource.com/plugins/owners/+/refs/heads/master/config.md

Signed-off-by: Nan Zhou <nanzhoumails@gmail.com>
Change-Id: Ic9639f5e6c83d4dee947c3fddc48de43f0d6aa61
diff --git a/OWNERS b/OWNERS
index ed73c5b..b0f9f11 100644
--- a/OWNERS
+++ b/OWNERS
@@ -78,28 +78,38 @@
 # unit tests
 - suffix: _test.cpp
   owners:
-      nanzhoumails@gmail.com
+      - nanzhoumails@gmail.com
 
 # Redfish schemas
 - exact: redfish-core/include/query.hpp
-      nanzhoumails@gmail.com
+  owners:
+      - nanzhoumails@gmail.com
 - exact: redfish-core/include/utils/query_param.hpp
-      nanzhoumails@gmail.com
+  owners:
+      - nanzhoumails@gmail.com
 - exact: redfish-core/lib/certificate_service.hpp
-      nanzhoumails@gmail.com
+  owners:
+      - nanzhoumails@gmail.com
 - exact: redfish-core/lib/log_service.hpp
-      nanzhoumails@gmail.com
+  owners:
+      - nanzhoumails@gmail.com
 - exact: redfish-core/lib/memory.hpp
-      nanzhoumails@gmail.com
+  owners:
+      - nanzhoumails@gmail.com
 - exact: redfish-core/lib/sensors.hpp
-      nanzhoumails@gmail.com
-      krzysztof.grobelny@intel.com
+  owners:
+      - nanzhoumails@gmail.com
+      - krzysztof.grobelny@intel.com
 - exact: redfish-core/lib/event_service.hpp
-      krzysztof.grobelny@intel.com
+  owners:
+      - krzysztof.grobelny@intel.com
 - exact: redfish-core/lib/power.hpp
-      krzysztof.grobelny@intel.com
+  owners:
+      - krzysztof.grobelny@intel.com
 - exact: redfish-core/lib/thermal.hpp
-      krzysztof.grobelny@intel.com
+  owners:
+      - krzysztof.grobelny@intel.com
 - exact: redfish-core/lib/virtual_media.hpp
-      krzysztof.grobelny@intel.com
+  owners:
+      - krzysztof.grobelny@intel.com