MAINTAINERS: Clarify UIO vs UIOVEC maintainer

The UIO file mask in MAINTAINERS was incorrectly directing UIOVEC
(include/linux/uio.h) patches to Greg.

Tag Al as the UIOVEC maintainer as Ingo and others have explicitly
required his ack before taking architecture patches that touch
lib/iov_iter.c.

Cc: Al Viro <viro@zeniv.linux.org.uk>
Reported-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

MAINTAINERS

@@ -15365,13 +15365,19 @@ F:	arch/x86/um/
 F:	fs/hostfs/
 F:	fs/hppfs/
 
+USERSPACE COPYIN/COPYOUT (UIOVEC)
+M:	Alexander Viro <viro@zeniv.linux.org.uk>
+S:	Maintained
+F:	lib/iov_iter.c
+F:	include/linux/uio.h
+
 USERSPACE I/O (UIO)
 M:	Greg Kroah-Hartman <gregkh@linuxfoundation.org>
 S:	Maintained
 T:	git git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc.git
 F:	Documentation/driver-api/uio-howto.rst
 F:	drivers/uio/
-F:	include/linux/uio*.h
+F:	include/linux/uio_driver.h
 
 UTIL-LINUX PACKAGE
 M:	Karel Zak <kzak@redhat.com>