all: fix remaining []array warnings

vlib/hash/wyhash/wyhash_test.v

@@ -28,15 +28,15 @@ fn test_wyhash() {
 	}
 }
 
-fn test_rand_u64() {	
+fn test_rand_u64() {
 	seed := u64(111)
-	mut rand_nos := []u64
+	mut rand_nos := []u64{}
 	for _ in 0..40 {
 		rand_no := wyhash.rand_u64(&seed)
 		for r in rand_nos {
 			assert rand_no != r
 		}
 		rand_nos << rand_no
-	}	
+	}
 	assert true
 }