Add missing decrement operator to I2C clockCount (#5292)

cores/esp8266/core_esp8266_si2c.c

@@ -293,24 +293,23 @@ unsigned char twi_readFrom(unsigned char address, unsigned char* buf, unsigned i
 }
 
 uint8_t twi_status() {
-    if (SCL_READ()==0) {
+    if (SCL_READ() == 0)
       return I2C_SCL_HELD_LOW; // SCL held low by another device, no procedure available to recover
-    }
+
     int clockCount = 20;
-    while (SDA_READ()==0 && clockCount>0) { // if SDA low, read the bits slaves have to sent to a max
+    while (SDA_READ() == 0 && clockCount-- > 0) { // if SDA low, read the bits slaves have to sent to a max
         twi_read_bit();
-        if (SCL_READ()==0) {
+        if (SCL_READ() == 0) {
           return I2C_SCL_HELD_LOW_AFTER_READ; // I2C bus error. SCL held low beyond slave clock stretch time
         }
     }
-    if (SDA_READ()==0) {
+    if (SDA_READ() == 0)
       return I2C_SDA_HELD_LOW; // I2C bus error. SDA line held low by slave/another_master after n bits.
-    }
-    if (!twi_write_start()) {
+
+    if (!twi_write_start())
       return I2C_SDA_HELD_LOW_AFTER_INIT;  // line busy. SDA again held low by another device. 2nd master?
-    } else {
-      return I2C_OK;
-    }
+
+    return I2C_OK;
 }
 
 uint8_t twi_transmit(const uint8_t* data, uint8_t length)