FLAT binaries: drop BINFMT_FLAT bad header magic warning

The warning issued by fs/binfmt_flat.c when the format handler is given a
non-FLAT and non-script executable is annoying to say the least when working
with FDPIC ELF objects.  If you build a kernel that supports both FLAT and
FDPIC ELFs on no-mmu, every time you execute an FDPIC ELF, the kernel spits
out this message.  While I understand a lot of newcomers to the no-mmu world
screw up generation of FLAT binaries, this warning is not usable for systems
that support more than just FLAT.

Signed-off-by: Jie Zhang <jie.zhang@analog.com>
Signed-off-by: Mike Frysinger <vapier@gentoo.org>
Cc: Bernd Schmidt <bernds_cb1@t-online.de>
Acked-by: Greg Ungerer <gerg@snapgear.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>