updatedb: DB's file path is not cpmpatible with MSYS2

[oech3]

See msys2/MINGW-packages#30059 (comment)

findutils/src/updatedb/mod.rs

Lines 85 to 86 in 2bc31fa

	// FIXME: the default should be platform-dependent
	.unwrap_or_else(|| PathBuf::from("/usr/local/var/locatedb")),