[SCSI] MAINTAINERS: Update zfcp entry

Steffen will take over the zfcp maintainer work. Update the
MAINTAINERS entry accordingly.
Acked-by: NSteffen Maier <maier@linux.vnet.ibm.com>
Acked-by: NSwen Schillig <swen@vnet.ibm.com>
Signed-off-by: NChristof Schmitt <christof.schmitt@de.ibm.com>
Signed-off-by: NJames Bottomley <James.Bottomley@suse.de>

MAINTAINERS

@@ -5306,8 +5306,7 @@ S:	Supported
 F:	drivers/s390/crypto/
 
 S390 ZFCP DRIVER
-M:	Christof Schmitt <christof.schmitt@de.ibm.com>
-M:	Swen Schillig <swen@vnet.ibm.com>
+M:	Steffen Maier <maier@linux.vnet.ibm.com>
 M:	linux390@de.ibm.com
 L:	linux-s390@vger.kernel.org
 W:	http://www.ibm.com/developerworks/linux/linux390/