staging: lustre: selftest: fix "not declared" by declaring in header

Fix several "symbol '...' was not declared" sparse warnings which
are caused by global variables by declaring them in the header file.
Signed-off-by: Jeremiah Mahler <jmmahler@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/staging/lustre/lnet/selftest/selftest.h

@@ -609,4 +609,16 @@ srpc_wait_service_shutdown(srpc_service_t *sv)
 	}
 }
 
+extern sfw_test_client_ops_t brw_test_client;
+void brw_init_test_client(void);
+
+extern srpc_service_t brw_test_service;
+void brw_init_test_service(void);
+
+extern sfw_test_client_ops_t ping_test_client;
+void ping_init_test_client(void);
+
+extern srpc_service_t ping_test_service;
+void ping_init_test_service(void);
+
 #endif /* __SELFTEST_SELFTEST_H__ */