MAINTAINERS: correct SECURITY SUBSYSTEM git entry
Use git.kernel.org not www.kernel.org
Signed-off-by: Joe Perches <joe@perches.com>
Cc: James Morris <jmorris@namei.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>