s390: remove generic email address from maintainers file

The public mailing lists and personal email addresses are sufficient.
No need for an extra generic email address.

Cc: Christian Borntraeger <borntraeger@de.ibm.com>
Acked-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Ursula Braun <ursula.braun@de.ibm.com>
Cc: Ingo Tuchscherer <ingo.tuchscherer@de.ibm.com>
Cc: Steffen Maier <maier@linux.vnet.ibm.com>
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

MAINTAINERS

@@ -5892,7 +5892,6 @@ F:	arch/powerpc/kvm/
 KERNEL VIRTUAL MACHINE for s390 (KVM/s390)
 M:	Christian Borntraeger <borntraeger@de.ibm.com>
 M:	Cornelia Huck <cornelia.huck@de.ibm.com>
-M:	linux390@de.ibm.com
 L:	linux-s390@vger.kernel.org
 W:	http://www.ibm.com/developerworks/linux/linux390/
 S:	Supported
@@ -8689,7 +8688,6 @@ F:	drivers/video/fbdev/savage/
 S390
 M:	Martin Schwidefsky <schwidefsky@de.ibm.com>
 M:	Heiko Carstens <heiko.carstens@de.ibm.com>
-M:	linux390@de.ibm.com
 L:	linux-s390@vger.kernel.org
 W:	http://www.ibm.com/developerworks/linux/linux390/
 S:	Supported
@@ -8717,7 +8715,6 @@ F:	block/partitions/ibm.c
 
 S390 NETWORK DRIVERS
 M:	Ursula Braun <ursula.braun@de.ibm.com>
-M:	linux390@de.ibm.com
 L:	linux-s390@vger.kernel.org
 W:	http://www.ibm.com/developerworks/linux/linux390/
 S:	Supported
@@ -8734,23 +8731,20 @@ F:	drivers/pci/hotplug/s390_pci_hpc.c
 
 S390 ZCRYPT DRIVER
 M:	Ingo Tuchscherer <ingo.tuchscherer@de.ibm.com>
-M:	linux390@de.ibm.com
 L:	linux-s390@vger.kernel.org
 W:	http://www.ibm.com/developerworks/linux/linux390/
 S:	Supported
 F:	drivers/s390/crypto/
 
 S390 ZFCP DRIVER
 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/
 S:	Supported
 F:	drivers/s390/scsi/zfcp_*
 
 S390 IUCV NETWORK LAYER
 M:	Ursula Braun <ursula.braun@de.ibm.com>
-M:	linux390@de.ibm.com
 L:	linux-s390@vger.kernel.org
 W:	http://www.ibm.com/developerworks/linux/linux390/
 S:	Supported