Return MODE_ERROR from sudoers_policy_deserialize_info() instead

of calling fatalx().

plugins/sudoers/sudoers.h

@@ -145,6 +145,7 @@ struct sudo_user {
 #define MODE_HELP		0x00000040
 #define MODE_LIST		0x00000080
 #define MODE_CHECK		0x00000100
+#define MODE_ERROR		0x00000200
 #define MODE_MASK		0x0000ffff
 
 /* Mode flags */