refactor(libraries/Wire): remove unused variables

Compiler reports "Wire.cpp:337:15: error: variable 'err' set but not used [-Werror=unused-but-set-variable]".

Author: safocl

libraries/Wire/src/Wire.cpp

@@ -334,7 +334,6 @@ bool TwoWire::begin(int sdaPin, int sclPin, uint32_t frequency)
 
 void TwoWire::end()
 {
-    esp_err_t err = ESP_OK;
 #if !CONFIG_DISABLE_HAL_LOCKS
     if(lock != NULL){
         //acquire lock
@@ -345,14 +344,14 @@ void TwoWire::end()
 #endif
 #if SOC_I2C_SUPPORT_SLAVE
         if(is_slave){
-            err = i2cSlaveDeinit(num);
+            esp_err_t err = i2cSlaveDeinit(num);
             if(err == ESP_OK){
                 is_slave = false;
             }
         } else
 #endif /* SOC_I2C_SUPPORT_SLAVE */
         if(i2cIsInit(num)){
-            err = i2cDeinit(num);
+            i2cDeinit(num);
         }
         freeWireBuffer();
 #if !CONFIG_DISABLE_HAL_LOCKS