LSM: Fix type of id parameter in kernel_post_load_data prototype

Clang warns:

security/security.c:1716:59: warning: implicit conversion from
enumeration type 'enum kernel_load_data_id' to different enumeration
type 'enum kernel_read_file_id' [-Wenum-conversion]
        ret = call_int_hook(kernel_post_load_data, 0, buf, size, id,
              ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~^~~
security/security.c:715:22: note: expanded from macro 'call_int_hook'
                        RC = P->hook.FUNC(__VA_ARGS__);         \
                             ~            ^~~~~~~~~~~
1 warning generated.

There is a mismatch between the id parameter type in
security_kernel_post_load_data and the function pointer prototype that
is created by the LSM_HOOK macro in the security_list_options union. Fix
the type in the LSM_HOOK macro as 'enum kernel_load_data_id' is what is
expected.

Fixes: b64fcae ("LSM: Introduce kernel_post_load_data() hook")
Acked-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Nathan Chancellor <natechancellor@gmail.com>
Link: https://lore.kernel.org/r/20201006201115.716550-1-natechancellor@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Author: nathanchance

include/linux/lsm_hook_defs.h

@@ -186,7 +186,7 @@ LSM_HOOK(int, 0, kernel_create_files_as, struct cred *new, struct inode *inode)
 LSM_HOOK(int, 0, kernel_module_request, char *kmod_name)
 LSM_HOOK(int, 0, kernel_load_data, enum kernel_load_data_id id, bool contents)
 LSM_HOOK(int, 0, kernel_post_load_data, char *buf, loff_t size,
-	 enum kernel_read_file_id id, char *description)
+	 enum kernel_load_data_id id, char *description)
 LSM_HOOK(int, 0, kernel_read_file, struct file *file,
 	 enum kernel_read_file_id id, bool contents)
 LSM_HOOK(int, 0, kernel_post_read_file, struct file *file, char *buf,