[wpilibc] MotorSafety::GetDescription(): Return std::string (#3390)

This is only called in an error condition, so it's not necessary to over
optimize it.

wpilibc/src/main/native/cpp/MotorSafety.cpp

@@ -8,8 +8,6 @@
 #include <utility>
 
 #include <wpi/SmallPtrSet.h>
-#include <wpi/SmallString.h>
-#include <wpi/raw_ostream.h>
 
 #include "frc/DriverStation.h"
 #include "frc/Errors.h"
@@ -90,11 +88,8 @@ void MotorSafety::Check() {
   }
 
   if (stopTime < Timer::GetFPGATimestamp()) {
-    wpi::SmallString<128> buf;
-    wpi::raw_svector_ostream desc(buf);
-    GetDescription(desc);
     FRC_ReportError(err::Timeout, "{}... Output not updated often enough",
-                    desc.str());
+                    GetDescription());
     StopMotor();
   }
 }

wpilibc/src/main/native/cpp/Relay.cpp

@@ -6,12 +6,12 @@
 
 #include <utility>
 
+#include <fmt/format.h>
 #include <hal/FRCUsageReporting.h>
 #include <hal/HALBase.h>
 #include <hal/Ports.h>
 #include <hal/Relay.h>
 #include <wpi/StackTrace.h>
-#include <wpi/raw_ostream.h>
 
 #include "frc/Errors.h"
 #include "frc/SensorUtil.h"
@@ -168,8 +168,8 @@ void Relay::StopMotor() {
   Set(kOff);
 }
 
-void Relay::GetDescription(wpi::raw_ostream& desc) const {
-  desc << "Relay " << GetChannel();
+std::string Relay::GetDescription() const {
+  return fmt::format("Relay {}", GetChannel());
 }
 
 void Relay::InitSendable(SendableBuilder& builder) {

wpilibc/src/main/native/cpp/drive/DifferentialDrive.cpp

@@ -189,8 +189,8 @@ void DifferentialDrive::StopMotor() {
   Feed();
 }
 
-void DifferentialDrive::GetDescription(wpi::raw_ostream& desc) const {
-  desc << "DifferentialDrive";
+std::string DifferentialDrive::GetDescription() const {
+  return "DifferentialDrive";
 }
 
 void DifferentialDrive::InitSendable(SendableBuilder& builder) {

wpilibc/src/main/native/cpp/drive/KilloughDrive.cpp

@@ -114,8 +114,8 @@ void KilloughDrive::StopMotor() {
   Feed();
 }
 
-void KilloughDrive::GetDescription(wpi::raw_ostream& desc) const {
-  desc << "KilloughDrive";
+std::string KilloughDrive::GetDescription() const {
+  return "KilloughDrive";
 }
 
 void KilloughDrive::InitSendable(SendableBuilder& builder) {

wpilibc/src/main/native/cpp/drive/MecanumDrive.cpp

@@ -109,8 +109,8 @@ MecanumDrive::WheelSpeeds MecanumDrive::DriveCartesianIK(double ySpeed,
           wheelSpeeds[kRearLeft], wheelSpeeds[kRearRight]};
 }
 
-void MecanumDrive::GetDescription(wpi::raw_ostream& desc) const {
-  desc << "MecanumDrive";
+std::string MecanumDrive::GetDescription() const {
+  return "MecanumDrive";
 }
 
 void MecanumDrive::InitSendable(SendableBuilder& builder) {

wpilibc/src/main/native/cpp/motorcontrol/NidecBrushless.cpp

@@ -4,8 +4,8 @@
 
 #include "frc/motorcontrol/NidecBrushless.h"
 
+#include <fmt/format.h>
 #include <hal/FRCUsageReporting.h>
-#include <wpi/raw_ostream.h>
 
 #include "frc/smartdashboard/SendableBuilder.h"
 #include "frc/smartdashboard/SendableRegistry.h"
@@ -64,8 +64,8 @@ void NidecBrushless::StopMotor() {
   m_pwm.SetDisabled();
 }
 
-void NidecBrushless::GetDescription(wpi::raw_ostream& desc) const {
-  desc << "Nidec " << GetChannel();
+std::string NidecBrushless::GetDescription() const {
+  return fmt::format("Nidec {}", GetChannel());
 }
 
 int NidecBrushless::GetChannel() const {

wpilibc/src/main/native/cpp/motorcontrol/PWMMotorController.cpp

@@ -4,7 +4,7 @@
 
 #include "frc/motorcontrol/PWMMotorController.h"
 
-#include <wpi/raw_ostream.h>
+#include <fmt/format.h>
 
 #include "frc/smartdashboard/SendableBuilder.h"
 
@@ -34,8 +34,8 @@ void PWMMotorController::StopMotor() {
   Disable();
 }
 
-void PWMMotorController::GetDescription(wpi::raw_ostream& desc) const {
-  desc << "PWM " << GetChannel();
+std::string PWMMotorController::GetDescription() const {
+  return fmt::format("PWM {}", GetChannel());
 }
 
 int PWMMotorController::GetChannel() const {