[PATCH blktests] Restore support for running tests without prior test results

[Bart Van Assche <bvanassche@xxxxxxx>]

This patch fixes the following runtime error:

./check: line 245: LAST_TEST_RUN: unbound variable

Fixes: 203b5723a28e ("Show last run for skipped tests")
Signed-off-by: Bart Van Assche <bvanassche@xxxxxxx>
---
 check | 8 +++++++-
 1 file changed, 7 insertions(+), 1 deletion(-)

diff --git a/check b/check
index 0a4e539a5cd9..5151d01995ac 100755
--- a/check
+++ b/check
@@ -240,9 +240,15 @@ _output_last_test_run() {
 }
 
 _output_test_run() {
+	local param_count
 	if [[ -t 1 ]]; then
 		# Move the cursor back up to the status.
-		tput cuu $((${#LAST_TEST_RUN[@]} + 1))
+		if [ -n "${LAST_TEST_RUN+set}" ]; then
+			param_count=${#LAST_TEST_RUN[@]}
+		else
+			param_count=0
+		fi
+		tput cuu $((param_count + 1))
 	fi
 
 	local status=${TEST_RUN["status"]}