lib: test_objpool: make global variables static

Kernel test robot reported build warnings that structures g_ot_sync_ops,
g_ot_async_ops and g_testcases should be static. These definitions are
only used in test_objpool.c, so make them static

Link: https://lore.kernel.org/all/20231108012248.313574-1-wuqiang.matt@bytedance.com/Reported-by: kernel test robot <lkp@intel.com>
Closes: https://lore.kernel.org/oe-kbuild-all/202311071229.WGrWUjM1-lkp@intel.com/Signed-off-by: wuqiang.matt <wuqiang.matt@bytedance.com>
Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>

lib/test_objpool.c

@@ -311,7 +311,7 @@ static void ot_fini_sync(struct ot_context *sop)
 	ot_kfree(sop->test, sop, sizeof(*sop));
 }
 
-struct {
+static struct {
 	struct ot_context * (*init)(struct ot_test *oc);
 	void (*fini)(struct ot_context *sop);
 } g_ot_sync_ops[] = {
@@ -475,7 +475,7 @@ static struct ot_context *ot_init_async_m0(struct ot_test *test)
 	return sop;
 }
 
-struct {
+static struct {
 	struct ot_context * (*init)(struct ot_test *oc);
 	void (*fini)(struct ot_context *sop);
 } g_ot_async_ops[] = {
@@ -632,7 +632,7 @@ static int ot_start_async(struct ot_test *test)
 #define NODE_COMPACT sizeof(struct ot_node)
 #define NODE_VMALLOC (512)
 
-struct ot_test g_testcases[] = {
+static struct ot_test g_testcases[] = {
 
 	/* sync & normal */
 	{0, 0, NODE_COMPACT, 1000, 0,  1,  0,  0, "sync: percpu objpool"},