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

devices/src/legacy/fw_cfg.rs

@@ -798,7 +798,7 @@ impl BusDevice for FwCfg {
 }
 
 #[cfg(test)]
-mod tests {
+mod unit_tests {
     use std::ffi::CString;
     use std::io::Write;
 

devices/src/legacy/gpio_pl061.rs

@@ -323,7 +323,7 @@ impl Transportable for Gpio {}
 impl Migratable for Gpio {}
 
 #[cfg(test)]
-mod tests {
+mod unit_tests {
     use vm_device::interrupt::{InterruptIndex, InterruptSourceConfig};
     use vmm_sys_util::eventfd::EventFd;
 

devices/src/legacy/rtc_pl031.rs

@@ -216,7 +216,7 @@ impl BusDevice for Rtc {
 }
 
 #[cfg(test)]
-mod tests {
+mod unit_tests {
     use super::*;
     use crate::{
         read_be_u16, read_be_u32, read_le_i32, read_le_u16, read_le_u64, write_be_u16,

devices/src/legacy/serial.rs

@@ -340,7 +340,7 @@ impl Transportable for Serial {}
 impl Migratable for Serial {}
 
 #[cfg(test)]
-mod tests {
+mod unit_tests {
     use std::sync::Mutex;
 
     use vm_device::interrupt::{InterruptIndex, InterruptSourceConfig};

devices/src/legacy/uart_pl011.rs

@@ -453,7 +453,7 @@ impl Transportable for Pl011 {}
 impl Migratable for Pl011 {}
 
 #[cfg(test)]
-mod tests {
+mod unit_tests {
     use std::sync::Mutex;
 
     use vm_device::interrupt::{InterruptIndex, InterruptSourceConfig};

devices/src/tpm.rs

@@ -531,7 +531,7 @@ impl BusDevice for Tpm {
 }
 
 #[cfg(test)]
-mod tests {
+mod unit_tests {
     use super::*;
 
     #[test]