media: cec-core.rst/cec-ioc-receive.rst: clarify CEC_TX_STATUS_ERROR

CEC_TX_STATUS_ERROR can be used if the HW cannot tell LOST_ARB and
LOW_DRIVE apart, or when some other error occurs. It is not a
replacement for NACK.

So the hardware must be able to tell the difference between OK, NACK and
'something else'.

Clarify the documentation (both public and kernel API) on this point.

Also fix two small typos (this messages -> this message).

Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
diff --git a/Documentation/media/kapi/cec-core.rst b/Documentation/media/kapi/cec-core.rst
index 2886625..d37e107 100644
--- a/Documentation/media/kapi/cec-core.rst
+++ b/Documentation/media/kapi/cec-core.rst
@@ -227,8 +227,8 @@
 	retransmission.
 
 CEC_TX_STATUS_ERROR:
-	some unspecified error occurred: this can be one of
-	the previous two if the hardware cannot differentiate or something
+	some unspecified error occurred: this can be one of ARB_LOST
+	or LOW_DRIVE if the hardware cannot differentiate or something
 	else entirely.
 
 CEC_TX_STATUS_MAX_RETRIES:
@@ -238,6 +238,9 @@
 	doesn't have to make another attempt to transmit the message
 	since the hardware did that already.
 
+The hardware must be able to differentiate between OK, NACK and 'something
+else'.
+
 The \*_cnt arguments are the number of error conditions that were seen.
 This may be 0 if no information is available. Drivers that do not support
 hardware retry can just set the counter corresponding to the transmit error