library: normalized the 'read_failed' guys across APIs
This patch will condense some logic in those functions
associated with the file input operations. The changes
will not, for the most part, alter any generated code.
More significantly (though not very) was the change to
two 'strtoul' calls. Since the returned 'endptr' value
isn't exploited, when that parm is set to NULL, we can
save one instruction on each side of such calls (wow).
Signed-off-by: Jim Warner <james.warner@comcast.net>