Fix configuration short name in key-exchanges.pl
This is testing with $kex, not without $kex, so use $kex, not "-$kex".
In test-ref-configs.pl, use $conf rather than "$conf". This is purely
a matter of Perl coding style.
diff --git a/tests/scripts/key-exchanges.pl b/tests/scripts/key-exchanges.pl
index bfde069..9cfa2d3 100755
--- a/tests/scripts/key-exchanges.pl
+++ b/tests/scripts/key-exchanges.pl
@@ -45,7 +45,7 @@
print "\n******************************************\n";
print "* Testing with key exchange: $kex\n";
print "******************************************\n";
- $ENV{MBEDTLS_TEST_CONFIGURATION} = "-$kex";
+ $ENV{MBEDTLS_TEST_CONFIGURATION} = $kex;
# full config with all key exchanges disabled except one
system( "scripts/config.pl full" ) and abort "Failed config full\n";