selftests/sysctl: Make sysctl test driver as a module

Fix config file to require CONFIG_TEST_SYSCTL=m instead of y
because this driver introduces a test sysctl interfaces which
are normally not used, and only used for the selftest.

Signed-off-by: Masami Hiramatsu <[email protected]>
Reviewed-by: Kees Cook <[email protected]>
Reviewed-by: Luis Chamberlain <[email protected]>
Signed-off-by: Shuah Khan <[email protected]>

Author: mhiramat

tools/testing/selftests/sysctl/config

@@ -1 +1 @@
-CONFIG_TEST_SYSCTL=y
+CONFIG_TEST_SYSCTL=m