test: avoid TEST-70 passphrase and password file mode complaints

Minor change, to adjust mode of /tmp/passphrase and /tmp/password test files to
avoid repeated warning logs that each file "...has 0644 mode that is too
permissive, please adjust the ownership and access mode."

test/units/testsuite-70.sh

@@ -41,6 +41,8 @@ tpm_check_failure_with_wrong_pin() {
 img="/tmp/test.img"
 truncate -s 20M "$img"
 echo -n passphrase >/tmp/passphrase
+# Change file mode to avoid "/tmp/passphrase has 0644 mode that is too permissive" messages
+chmod 0600 /tmp/passphrase
 cryptsetup luksFormat -q --pbkdf pbkdf2 --pbkdf-force-iterations 1000 --use-urandom "$img" /tmp/passphrase
 
 # Unlocking via keyfile
@@ -259,6 +261,8 @@ cryptenroll_wipe_and_check() {(
 img="/tmp/cryptenroll.img"
 truncate -s 20M "$img"
 echo -n password >/tmp/password
+# Change file mode to avoid "/tmp/password has 0644 mode that is too permissive" messages
+chmod 0600 /tmp/password
 cryptsetup luksFormat -q --pbkdf pbkdf2 --pbkdf-force-iterations 1000 --use-urandom "$img" /tmp/password
 
 # Enroll additional tokens, keys, and passwords to exercise the list and wipe stuff