Fix warnings lld

[lbartoletti]

Tiny fix, to add long long identifier for PRId64 instead of simple long

[nilason]

It doesn't look correct, you add a specifier lld before the macro PRId64 which should add that (platform specific) specifier in the first place.

To be sure the definition of grass_int64

https://github.com/OSGeo/grass/blob/c64690d871af93dfc2adcf4a8bf97b7f67b1a95a/include/grass/gis.h#L638-L650

should now (being C11 code) always be int64_t.

(Besides, you have a lot of unrelated format changes).