Remove initialization of big holes in syscallent.h files

Remove initialization of big holes in syscallent.h files

There is no need to explicitly initialize big holes after conversion
of syscallent.h files to use designated initializers.  For architectures
that have some data at the end of syscallent.h this initialization of
big holes is no-op, for others it just inflates the table unnecessarily.

* linux/arc/syscallent.h: Remove initialization of arch specific block
at the end of table.
* linux/metag/syscallent.h: Likewise.
* linux/nios2/syscallent.h: Likewise.
* linux/or1k/syscallent.h: Likewise.
* linux/tile/syscallent.h: Likewise.
* linux/tile/syscallent1.h: Likewise.
* linux/arm/syscallent.h: Remove explicit initialization of a big hole
before socket subcalls.
* linux/i386/syscallent.h: Likewise.
* linux/m68k/syscallent.h: Likewise.
* linux/mips/syscallent-n32.h: Likewise.
* linux/powerpc/syscallent.h: Likewise.
* linux/powerpc64/syscallent.h: Likewise.
* linux/s390/syscallent.h: Likewise.
* linux/s390x/syscallent.h: Likewise.
* linux/sh/syscallent.h: Likewise.
* linux/sh64/syscallent.h: Likewise.
* linux/sparc/syscallent.h: Likewise.
* linux/sparc64/syscallent.h: Likewise.
* linux/mips/syscallent-compat.h: Remove explicit initialization
of big holes between different mips ABIs.
* linux/mips/syscallent-n64.h: Remove explicit initialization
of big holes before socket subcalls and between different mips ABIs.
* linux/mips/syscallent-o32.h: Likewise.