s390: remove bogus system call table entries

s390: remove bogus system call table entries

The 64 bit system call table contains three entries that come without
a matching NR_<name> entry in unistd.h.  In fact all three of them do
not make sense on 64 bit, but only for compat processes.

llseek and mmap2 were specifically introduced for 32 bit / compat
processes. getrlimit is wired up twice, so that only the entry that
comes with a corresponding NR_getrlimit needs to be kept.

The other entries can be removed, since it seems very unlikely that
this will break user space.

Reported-by: Hendrik Brueckner <brueckner@linux.vnet.ibm.com>
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>