cipher: Avoid signed divisions in idea.c
* cipher/idea.c (mul_inv): Use unsigned division.
Hello, all. While compiling in an environment with only libgcc subset for ARM, I found out that idea.c uses signed divisions: Reading the code this seems to be unintended. Inlined patch replaces them with more appropriate unsigned division.
- Reported-by: Vladimir 'φ-coder/phcoder' Serbinenko <phcoder@gmail.com>
- Signed-off-by: Werner Koch <wk@gnupg.org>