x86/cpu: Remove misleading comment

The comment of the "#endif" after setup_disable_pku() is wrong.

As the related #ifdef is only a few lines above, just remove the
comment.
Signed-off-by: Juergen Gross <jgross@suse.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lore.kernel.org/r/20230113130126.1966-1-jgross@suse.com

arch/x86/kernel/cpu/common.c

@@ -567,7 +567,7 @@ static __init int setup_disable_pku(char *arg)
 	return 1;
 }
 __setup("nopku", setup_disable_pku);
-#endif /* CONFIG_X86_64 */
+#endif
 
 #ifdef CONFIG_X86_KERNEL_IBT