testsuite: fix duration tests in t2700-mini-cmd.t

Problem: The duration tests in t2700-mini-cmd.t use jq incorrectly,
so the tests are not checking that the actual jobspec duration value
matches the expected result.

Fix the broken tests.

Author: grondo

t/t2700-mini-cmd.t

@@ -98,19 +98,19 @@ test_expect_success 'flux mini run -vvv produces exec events on stderr' '
 '
 test_expect_success HAVE_JQ 'flux mini submit --time-limit=5d works' '
 	flux mini submit --dry-run --time-limit=5d hostname >t5d.out &&
-	jq -r ".attributes.system.duration == 432000"
+	jq -e ".attributes.system.duration == 432000" < t5d.out
 '
 test_expect_success HAVE_JQ 'flux mini submit --time-limit=4h works' '
 	flux mini submit --dry-run --time-limit=4h hostname >t4h.out &&
-	jq -r ".attributes.system.duration == 14400"
+	jq -e ".attributes.system.duration == 14400" < t4h.out
 '
 test_expect_success HAVE_JQ 'flux mini submit --time-limit=1m works' '
 	flux mini submit --dry-run --time-limit=5m hostname >t5m.out &&
-	jq -r ".attributes.system.duration == 300"
+	jq -e ".attributes.system.duration == 300" < t5m.out
 '
 test_expect_success HAVE_JQ 'flux mini submit -t5s works' '
 	flux mini submit --dry-run -t5s hostname >t5s.out &&
-	jq -r ".attributes.system.duration == 300"
+	jq -e ".attributes.system.duration == 5" < t5s.out
 '
 test_expect_success HAVE_JQ 'flux mini submit -t5 works' '
 	flux mini submit --dry-run -t5 hostname >t5.out &&