Fix missing return value in getBemf() method of Haptic_Driver.cpp

[ShijiMi-Soup]

Problem

While trying the I2C_mode example using Arduino IDE 2.3.4, I encountered the following error during compilation:

/Users/takahiro/Documents/Arduino/libraries/SparkFun_Qwiic_Haptic_Driver_DA7280_Library/src/Haptic_Driver.cpp: In member function 'float Haptic_Driver::getBemf()':
/Users/takahiro/Documents/Arduino/libraries/SparkFun_Qwiic_Haptic_Driver_DA7280_Library/src/Haptic_Driver.cpp:502:1: error: control reaches end of non-void function [-Werror=return-type]
  502 | }
      | ^
cc1plus: some warnings being treated as errors

exit status 1

Compilation error: exit status 1

It seems the issue is that the getBemf() method not having a default return value, even though it is declared to return a float. The error occurs even when I only import "Haptic_Driver.h" without using the library in my code, which suggests it is an issue with the library's implementation rather than usage.

Fix

I added a return 0.0 at the end of the method as a workaround, and the example compiled successfully.

Concerns

I am unsure whether returning 0.0 is appropriate, as I am not familiar with the intended behavior of the getBemf() method. If another value is more appropriate, I am open to suggestions.