Fix Error in converting EddystoneTLM negative temperatures to float

[Max93]

In NimBLEEddystoneTLM.cpp, there is an issue when receiving negative numbers for temperature readings and when setting the temperature.

For example, a temperature of -0.1°C is incorrectly converted to approximately 256°C.

To address this issue, we made the following changes:

/**
 * @brief Set the temperature to advertise.
 * @param [in] temp The temperature value.
 */
void NimBLEEddystoneTLM::setTemp(float temp) {
-  m_eddystoneData.temp = (uint16_t)temp;
+  m_eddystoneData.temp = ENDIAN_CHANGE_U16((int16_t)(temp * 256.0f));
} // setTemp

/**
 * @brief Get the temperature being advertised.
 * @return The temperature value.
 */
float NimBLEEddystoneTLM::getTemp() {
-  return ENDIAN_CHANGE_U16(m_eddystoneData.temp) / 256.0f;
+  return (int16_t)ENDIAN_CHANGE_U16(m_eddystoneData.temp) / 256.0f;
} // getTemp

I am a colleague of Giovanni, who opened the issue #675

Thank you for considering this fix.