Coding - Incorrect return-value check for a 'scanf'-like function

[dpasukhi]

Fix sscanf condition checks in iges_lire function for better error handling

[Copilot]

Pull Request Overview

Fixes incorrect return value checks for sscanf calls in the iges_lire function to properly handle parsing errors when reading IGES file sections.

Key changes:

• Corrected sscanf return value validation to check for exactly 1 successful conversion instead of checking for non-zero or zero returns
• Ensures proper error handling when parsing numeric section identifiers from IGES file lines