[S390] fix vmlinux link when CONFIG_SYSIPC=n

Fix the following compile error:

  CC      init/version.o
  LD      init/built-in.o
  LD      .tmp_vmlinux1
arch/s390/kernel/built-in.o(.text+0xdba4): In function `sys32_ipc':
: undefined reference to `compat_sys_semtimedop'
arch/s390/kernel/built-in.o(.text+0xdbee): In function `sys32_ipc':
: undefined reference to `compat_sys_semctl'
arch/s390/kernel/built-in.o(.text+0xdc08): In function `sys32_ipc':
: undefined reference to `compat_sys_msgsnd'
arch/s390/kernel/built-in.o(.text+0xdc30): In function `sys32_ipc':
: undefined reference to `compat_sys_msgrcv'
arch/s390/kernel/built-in.o(.text+0xdc58): In function `sys32_ipc':
: undefined reference to `compat_sys_msgctl'
arch/s390/kernel/built-in.o(.text+0xdc76): In function `sys32_ipc':
: undefined reference to `compat_sys_shmat'
arch/s390/kernel/built-in.o(.text+0xdcb0): In function `sys32_ipc':
: undefined reference to `compat_sys_shmctl'
make: *** [.tmp_vmlinux1] Error 1

Signed-off-by: Cedric Le Goater <clg@fr.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
diff --git a/arch/s390/kernel/compat_linux.c b/arch/s390/kernel/compat_linux.c
index e15e148..2001767 100644
--- a/arch/s390/kernel/compat_linux.c
+++ b/arch/s390/kernel/compat_linux.c
@@ -295,6 +295,7 @@
  *
  * This is really horribly ugly.
  */
+#ifdef CONFIG_SYSVIPC
 asmlinkage long sys32_ipc(u32 call, int first, int second, int third, u32 ptr)
 {
 	if (call >> 16)		/* hack for backward compatibility */
@@ -338,6 +339,7 @@
 
 	return -ENOSYS;
 }
+#endif
 
 asmlinkage long sys32_truncate64(const char __user * path, unsigned long high, unsigned long low)
 {