LibSegFault uses piggybacks sc_fpstate field of the `struct sigcontext'
and this patch avoids LibSegFault overflowing this field.  Also this
removes an unnecessary divergence from classic m68k.
Signed-off-by: Maxim Kuvyrkov <maxim@codesourcery.com>
Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>