selftests/bpf: Close the file descriptor to avoid resource leaks

Static analysis found an issue in bench_htab_mem.c and sk_assign.c

cppcheck output before this patch:
tools/testing/selftests/bpf/benchs/bench_htab_mem.c:284:3: error: Resource leak: fd [resourceLeak]
tools/testing/selftests/bpf/prog_tests/sk_assign.c:41:3: error: Resource leak: tc [resourceLeak]

cppcheck output after this patch:
No resource leaks found

Fix the issue by closing the file descriptors fd and tc.

Signed-off-by: Malaya Kumar Rout <[email protected]>
Signed-off-by: Andrii Nakryiko <[email protected]>
Link: https://lore.kernel.org/bpf/[email protected]

Author: malayarout91

tools/testing/selftests/bpf/benchs/bench_htab_mem.c

@@ -279,15 +279,14 @@ static void htab_mem_read_mem_cgrp_file(const char *name, unsigned long *value)
 	}
 
 	got = read(fd, buf, sizeof(buf) - 1);
+	close(fd);
 	if (got <= 0) {
 		*value = 0;
 		return;
 	}
 	buf[got] = 0;
 
 	*value = strtoull(buf, NULL, 0);
-
-	close(fd);
 }
 
 static void htab_mem_measure(struct bench_res *res)

tools/testing/selftests/bpf/prog_tests/sk_assign.c

@@ -37,8 +37,10 @@ configure_stack(void)
 	tc = popen("tc -V", "r");
 	if (CHECK_FAIL(!tc))
 		return false;
-	if (CHECK_FAIL(!fgets(tc_version, sizeof(tc_version), tc)))
+	if (CHECK_FAIL(!fgets(tc_version, sizeof(tc_version), tc))) {
+		pclose(tc);
 		return false;
+	}
 	if (strstr(tc_version, ", libbpf "))
 		prog = "test_sk_assign_libbpf.bpf.o";
 	else