avutil/softfloat: use abort() instead of av_assert0(0)

Fixes compilation of host tool aacps_fixed_tablegen.
Reviewed-by: Michael Niedermayer <michael@niedermayer.cc>
Signed-off-by: James Almer <jamrial@gmail.com>

libavutil/softfloat.h

@@ -180,7 +180,7 @@ static av_always_inline SoftFloat av_sqrt_sf(SoftFloat val)
     if (val.mant == 0)
         val.exp = MIN_EXP;
     else if (val.mant < 0)
-        av_assert0(0);
+        abort();
     else
     {
         tabIndex = (val.mant - 0x20000000) >> 20;