STM32: Remove i2c_read() and i2c_write() redirects to HAL_I2C_IsDeviceReady()

Some I2C devices require specific zero length read/write sequences which
the HAL_I2C_IsDeviceReady() redirect interferes with.  After Removing
these redirects, it was confirmed that zero length reads and writes
would both still work correctly for detecting presence/absence of an
I2C device on a bus.

Author: bscott-zebra

targets/TARGET_STM/i2c_api.c

@@ -743,13 +743,6 @@ int i2c_read(i2c_t *obj, int address, char *data, int length, int stop) {
     int count = I2C_ERROR_BUS_BUSY, ret = 0;
     uint32_t timeout = 0;
 
-    if((length == 0) || (data == 0)) {
-        if(HAL_I2C_IsDeviceReady(handle, address, 1, 10) == HAL_OK)
-            return 0;
-        else
-            return I2C_ERROR_BUS_BUSY;
-    }
-
     if ((obj_s->XferOperation == I2C_FIRST_AND_LAST_FRAME) ||
         (obj_s->XferOperation == I2C_LAST_FRAME)) {
         if (stop)
@@ -802,13 +795,6 @@ int i2c_write(i2c_t *obj, int address, const char *data, int length, int stop) {
     int count = I2C_ERROR_BUS_BUSY, ret = 0;
     uint32_t timeout = 0;
 
-    if((length == 0) || (data == 0)) {
-        if(HAL_I2C_IsDeviceReady(handle, address, 1, 10) == HAL_OK)
-            return 0;
-        else
-            return I2C_ERROR_BUS_BUSY;
-    }
-
     if ((obj_s->XferOperation == I2C_FIRST_AND_LAST_FRAME) ||
         (obj_s->XferOperation == I2C_LAST_FRAME)) {
         if (stop)