Fix PR 101230: ICE in fold_cond_expr_with_comparison
This fixes PR 101230 where I had messed up and forgot that
invert_tree_comparison can return ERROR_MARK if the comparsion
is not invertable (floating point types).
Committed as obvious after a bootstrap/test on x86_64-linux-gnu-gnu
gcc/ChangeLog:
PR middle-end/101230
* fold-const.c (fold_ternary_loc): Check
the return value of invert_tree_comparison.