Bugfix Channel Scan

This Commit,
- Fixes Bug with Channel scan

Author: codenio

adafruit_tca9548a.py

@@ -77,7 +77,12 @@ def writeto_then_readfrom(self, address, buffer_out, buffer_in, **kwargs):
 
     def scan(self):
         """Perform an I2C Device Scan"""
-        return self.tca.i2c.scan()
+        addresses = []
+        if self.try_lock():
+            addresses = self.tca.i2c.scan()
+            self.unlock()
+
+        return addresses
 
 
 class TCA9548A: