s390/compat: change default for CONFIG_COMPAT to "n"

31 bit support has been removed from the kernel more than eight years
ago. The last 31 bit distribution is many years older. There shouldn't be
any 31 bit code around anymore.

Therefore avoid providing an unused and only partially tested user space
interface and change the default for CONFIG_COMPAT from "yes" to "no".
Acked-by: Christian Borntraeger <borntraeger@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>

arch/s390/Kconfig

@@ -443,7 +443,7 @@ config COMMAND_LINE_SIZE
 	  line.
 
 config COMPAT
-	def_bool y
+	def_bool n
 	prompt "Kernel support for 31 bit emulation"
 	select ARCH_WANT_OLD_COMPAT_IPC
 	select COMPAT_OLD_SIGACTION
@@ -454,7 +454,9 @@ config COMPAT
 	  Select this option if you want to enable your system kernel to
 	  handle system-calls from ELF binaries for 31 bit ESA.  This option
 	  (and some other stuff like libraries and such) is needed for
-	  executing 31 bit applications.  It is safe to say "Y".
+	  executing 31 bit applications.
+
+	  If unsure say N.
 
 config SMP
 	def_bool y

arch/s390/configs/zfcpdump_defconfig

@@ -10,7 +10,6 @@ CONFIG_BLK_DEV_INITRD=y
 CONFIG_CC_OPTIMIZE_FOR_SIZE=y
 CONFIG_CRASH_DUMP=y
 CONFIG_MARCH_Z13=y
-# CONFIG_COMPAT is not set
 CONFIG_NR_CPUS=2
 CONFIG_HZ_100=y
 # CONFIG_CHSC_SCH is not set