nvme: update tls_key() handling

Few misc issues in current tls_key() implementation:

1) Additional blank line printed in err message if the keyfile
cannot be opened.

2) For export, nvme_scan_tls_keys() can return positive values too
for successful scenarios. So this currently leads to erroneous return
value handling.

3) For import, no return value checking for import_key() failure
scenarios.

4) For revoke, return appropriate error immediately when
nvme_revoke_tls_key() fails.

5) No helpful success message printed for all the options.

Fix the same.

Signed-off-by: Martin George <marting@netapp.com>

Author: martin-gpy

nvme.c

@@ -9515,7 +9515,7 @@ static int tls_key(int argc, char **argv, struct command *command, struct plugin
 
 		fd = fopen(cfg.keyfile, mode);
 		if (!fd) {
-			nvme_show_error("Cannot open keyfile %s, error %d\n",
+			nvme_show_error("Cannot open keyfile %s, error %d",
 					cfg.keyfile, errno);
 			return -errno;
 		}
@@ -9536,16 +9536,36 @@ static int tls_key(int argc, char **argv, struct command *command, struct plugin
 		return -EINVAL;
 	} else if (cfg.export) {
 		err = nvme_scan_tls_keys(cfg.keyring, __scan_tls_key, fd);
-		if (err)
+		if (err < 0) {
 			nvme_show_error("Export of TLS keys failed with '%s'",
 				nvme_strerror(errno));
+			return err;
+		}
+
+		if (argconfig_parse_seen(opts, "verbose"))
+			printf("exporting to %s\n", cfg.keyfile);
+
+		return 0;
 	} else if (cfg.import) {
 		err = import_key(cfg.keyring, fd);
+		if (err) {
+			nvme_show_error("Import of TLS keys failed with '%s'",
+					nvme_strerror(errno));
+			return err;
+		}
+
+		if (argconfig_parse_seen(opts, "verbose"))
+			printf("importing from %s\n", cfg.keyfile);
 	} else {
 		err = nvme_revoke_tls_key(cfg.keyring, cfg.keytype, cfg.revoke);
-		if (err)
+		if (err) {
 			nvme_show_error("Failed to revoke key '%s'",
 					nvme_strerror(errno));
+			return err;
+		}
+
+		if (argconfig_parse_seen(opts, "verbose"))
+			printf("revoking key\n");
 	}
 
 	return err;