nvme: update the tls 'compat' option documentation

There are discrepancies in the tls 'compat' option documentation
across gen-tls-key and check-tls-key. Also the actual 'compat'
option description text is a little vague to the end user. Update
the same for better clarity.

Signed-off-by: Martin George <[email protected]>

Author: martin-gpy

Documentation/nvme-check-tls-key.txt

@@ -65,8 +65,8 @@ OPTIONS
 
 -C:
 --compat:
-	Use the original algorithm when deriving TLS keys for
-	compatibility with older implentations.
+	Use the original non-RFC 8446 compliant algorithm when
+	checking TLS keys for compatibility with older implentations.
 
 -f <keyfile>
 --keyfile=<keyfile>

nvme.c

@@ -9769,7 +9769,7 @@ static int gen_tls_key(int argc, char **argv, struct command *command, struct pl
 	const char *keytype = "Key type of the retained key.";
 	const char *insert = "Insert retained key into the keyring.";
 	const char *keyfile = "Update key file with the derive TLS PSK.";
-	const char *compat = "Use compatibility algorithm for HKDF-Expand-Label.";
+	const char *compat = "Use non-RFC 8446 compliant algorithm for deriving TLS PSK for older implementations";
 
 	_cleanup_free_ unsigned char *raw_secret = NULL;
 	_cleanup_free_ char *encoded_key = NULL;
@@ -9913,7 +9913,7 @@ static int check_tls_key(int argc, char **argv, struct command *command, struct
 	const char *keytype = "Key type of the retained key.";
 	const char *insert = "Insert retained key into the keyring.";
 	const char *keyfile = "Update key file with the derive TLS PSK.";
-	const char *compat = "Use compatibility algorithm for HKDF-Expand-Label.";
+	const char *compat = "Use non-RFC 8446 compliant algorithm for checking TLS PSK for older implementations.";
 
 	_cleanup_free_ unsigned char *decoded_key = NULL;
 	_cleanup_free_ char *hnqn = NULL;