zero_to_err_ptr: handle parse errors better

zero_to_err_ptr: handle parse errors better

One thing that I sometimes do is run smatch on code that can't compile
in a best effort sort of way.  In those cases, I ignore parse errors.
Where smatch doesn't know the type of a variable it ends up getting set
to long long type.  Ignore error pointer warnings in that situation.

Signed-off-by: Dan Carpenter <dan.carpenter@linaro.org>