selftests: bpf: fix use of undeclared RET_IF macro

commit 634efb75 ("selftests: bpf: Reset global state between
reuseport test runs") uses a macro RET_IF which doesn't exist in
the v4.19 tree. It is defined as follows:

        #define RET_IF(condition, tag, format...) ({
                if (CHECK_FAIL(condition)) {
                        printf(tag " " format);
                        return;
                }
        })

CHECK_FAIL in turn is defined as:

        #define CHECK_FAIL(condition) ({
                int __ret = !!(condition);
                int __save_errno = errno;
                if (__ret) {
                        test__fail();
                        fprintf(stdout, "%s:FAIL:%d\n", __func__, __LINE__);
                }
                errno = __save_errno;
                __ret;
        })

Replace occurences of RET_IF with CHECK. This will abort the test binary
if clearing the intermediate state fails.

Fixes: 634efb75 ("selftests: bpf: Reset global state between reuseport test runs")
Reported-by: kernel test robot <rong.a.chen@intel.com>
Signed-off-by: Lorenz Bauer <lmb@cloudflare.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

tools/testing/selftests/bpf/test_select_reuseport.c

@@ -616,13 +616,13 @@ static void cleanup_per_test(void)
 
 	for (i = 0; i < NR_RESULTS; i++) {
 		err = bpf_map_update_elem(result_map, &i, &zero, BPF_ANY);
-		RET_IF(err, "reset elem in result_map",
-		       "i:%u err:%d errno:%d\n", i, err, errno);
+		CHECK(err, "reset elem in result_map",
+		      "i:%u err:%d errno:%d\n", i, err, errno);
 	}
 
 	err = bpf_map_update_elem(linum_map, &zero, &zero, BPF_ANY);
-	RET_IF(err, "reset line number in linum_map", "err:%d errno:%d\n",
-	       err, errno);
+	CHECK(err, "reset line number in linum_map", "err:%d errno:%d\n",
+	      err, errno);
 
 	for (i = 0; i < REUSEPORT_ARRAY_SIZE; i++)
 		close(sk_fds[i]);