MAINTAINERS: Fix Andy's surname and the directory entries of VDSO

Fixes: e7098031 ("MAINTAINERS: Add entry for the generic VDSO library")
Reported-by: Joe Perches/ <joe@perches.com>
Reported-by: Andy Lutomirks^H^Hski <luto@kernel.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>