test.bash: pass flags on to "go vet"

Fixes this problem when openssl headers are not installed:

$ ./test-without-openssl.bash
gocryptfs v1.7-11-g8f2723b without_openssl; go-fuse v1.0.0-133-gcc423d1; 2019-03-31 go1.12.1
Package libcrypto was not found in the pkg-config search path.
Perhaps you should add the directory containing `libcrypto.pc'
to the PKG_CONFIG_PATH environment variable
No package 'libcrypto' found
pkg-config: exit status 1

test.bash

@@ -48,7 +48,7 @@ if ! go tool | grep vet > /dev/null ; then
 elif [[ -d vendor ]] ; then
 	echo "vendor directory exists, skipping 'go tool vet'"
 else
-	go vet .
+	go vet "$@" .
 fi
 
 #            We don't want all the subprocesses