tests: streamline module names to unit_tests

This better aligns with the rest of the code and makes it clearer
that these tests can run "as is" in a normal hosted environments
without the special test environment.

Signed-off-by: Philipp Schuster <philipp.schuster@cyberus-technology.de>
On-behalf-of: SAP philipp.schuster@sap.com

vm-allocator/src/address.rs

@@ -215,7 +215,7 @@ impl AddressAllocator {
 }
 
 #[cfg(test)]
-mod tests {
+mod unit_tests {
     use super::*;
 
     #[test]