Various drivers: Cloned logic. On error, memory was freed, but the error was not returned. It just continued as though no error happened.

drivers/i2c/i2c_driver.c

@@ -409,6 +409,7 @@ int i2c_register(FAR struct i2c_master_s *i2c, int bus)
            */
 
           kmm_free(priv);
+          return ret;
         }
 
       /* Return the result of the registration */

drivers/i2s/i2schar.c

@@ -439,6 +439,7 @@ int i2schar_register(FAR struct i2s_dev_s *i2s, int minor)
            */
 
           kmm_free(priv);
+          return ret;
         }
 
       /* Return the result of the registration */

drivers/spi/spi_driver.c

@@ -398,6 +398,7 @@ int spi_register(FAR struct spi_dev_s *spi, int bus)
            */
 
           kmm_free(priv);
+          return ret;
         }
 
       /* Return the result of the registration */

include/nuttx/analog/adc.h

@@ -128,7 +128,7 @@ struct adc_fifo_s
 
 /* This structure defines all of the operations providd by the architecture specific
  * logic.  All fields must be provided with non-NULL function pointers by the
- * caller of can_register().
+ * caller of adc_register().
  */
 
 struct adc_dev_s;