ranges: fix error pointer handling cross compiling on 32 bit systems

ranges: fix error pointer handling cross compiling on 32 bit systems

There are a few related fixes in this commit.  Smatch was doing stuff like:

	sval.uvalue >= -4905ULL

Where it should have been casted to the long of the system we are compiling
for.  if (sval_cmp(sval, valid_ptr_max_sval) > 0) {.

The other thing is that Smatch sort of treats error pointers as negatives.
Obviously they aren't but it's nicer from a UI perspective to print -12
for -ENOMEM instead of 18446744073709551604.  So I fixed that up as well.
It required writing a little sign_extend_err_ptr() function.

And then that required a fixup when we're reading -12 back from the DB
that it gets translated back into the correct value.  This was in
parse_val().

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