MAINTAINERS: update ceph entries

- The Ceph common code is used by both fs/ceph and drivers/block/rbd.
  Add a separate maintainers entry.

- Add Ilya as libceph maintainer and cephfs submaintainer.

- Attribute Documentation/ABI/testing/sysfs-bus-rbd to rbd.

- ceph-devel@vger.kernel.org should be L, not M in rbd entry.
Signed-off-by: Sage Weil <sage@redhat.com>
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>

MAINTAINERS

@@ -2562,19 +2562,29 @@ F:	arch/powerpc/include/uapi/asm/spu*.h
 F:	arch/powerpc/oprofile/*cell*
 F:	arch/powerpc/platforms/cell/
 
-CEPH DISTRIBUTED FILE SYSTEM CLIENT
+CEPH COMMON CODE (LIBCEPH)
+M:	Ilya Dryomov <idryomov@gmail.com>
 M:	"Yan, Zheng" <zyan@redhat.com>
 M:	Sage Weil <sage@redhat.com>
 L:	ceph-devel@vger.kernel.org
 W:	http://ceph.com/
 T:	git git://git.kernel.org/pub/scm/linux/kernel/git/sage/ceph-client.git
 S:	Supported
-F:	Documentation/filesystems/ceph.txt
-F:	fs/ceph/
 F:	net/ceph/
 F:	include/linux/ceph/
 F:	include/linux/crush/
 
+CEPH DISTRIBUTED FILE SYSTEM CLIENT (CEPH)
+M:	"Yan, Zheng" <zyan@redhat.com>
+M:	Sage Weil <sage@redhat.com>
+M:	Ilya Dryomov <idryomov@gmail.com>
+L:	ceph-devel@vger.kernel.org
+W:	http://ceph.com/
+T:	git git://git.kernel.org/pub/scm/linux/kernel/git/sage/ceph-client.git
+S:	Supported
+F:	Documentation/filesystems/ceph.txt
+F:	fs/ceph/
+
 CERTIFIED WIRELESS USB (WUSB) SUBSYSTEM:
 L:	linux-usb@vger.kernel.org
 S:	Orphan
@@ -8366,10 +8376,11 @@ RADOS BLOCK DEVICE (RBD)
 M:	Ilya Dryomov <idryomov@gmail.com>
 M:	Sage Weil <sage@redhat.com>
 M:	Alex Elder <elder@kernel.org>
-M:	ceph-devel@vger.kernel.org
+L:	ceph-devel@vger.kernel.org
 W:	http://ceph.com/
 T:	git git://git.kernel.org/pub/scm/linux/kernel/git/sage/ceph-client.git
 S:	Supported
+F:	Documentation/ABI/testing/sysfs-bus-rbd
 F:	drivers/block/rbd.c
 F:	drivers/block/rbd_types.h