RedfishPkg: Add missing FreePool to fix memory leak issue

According to the implementation of `HiiGetSupportedLanguages`, the caller
is responsible for freeing the returned string using FreePool().

Signed-off-by: Qihang Gao <gaoqihang@loongson.cn>

RedfishPkg/RedfishPlatformConfigDxe/RedfishPlatformConfigImpl.c

@@ -508,12 +508,16 @@ GetSupportedSchema (
   }
 
   if (Count == 0) {
+    FreePool (SupportedLanguages);
+
     return EFI_NOT_FOUND;
   }
 
   SupportedSchema->Count      = Count;
   SupportedSchema->SchemaList = AllocatePool (sizeof (CHAR8 *) * Count);
   if (SupportedSchema->SchemaList == NULL) {
+    FreePool (SupportedLanguages);
+
     return EFI_OUT_OF_RESOURCES;
   }
 
@@ -539,6 +543,8 @@ GetSupportedSchema (
     ++Index;
   }
 
+  FreePool (SupportedLanguages);
+
   return EFI_SUCCESS;
 }