Adjusts syscall.Statfs_t for OpenBSD

Here a small adjustmend for OpenBSD's syscall.Statfs_t which is backport
of https://github.com/openbsd/ports/blob/9c2aaca13bf333ac228677736b42f31cba441edd/sysutils/docker-buildx/patches/patch-vendor_github_com_moby_buildkit_cmd_buildkitd_config_gcpolicy_unix_go

Signed-off-by: Kirill A. Korinsky <[email protected]>

Author: catap

cmd/buildkitd/config/gcpolicy_openbsd.go

@@ -0,0 +1,19 @@
+//go:build openbsd
+// +build openbsd
+
+package config
+
+import (
+	"syscall"
+)
+
+var DiskSpacePercentage int64 = 10
+
+func getDiskSize(root string) (int64, error) {
+	var st syscall.Statfs_t
+	if err := syscall.Statfs(root, &st); err != nil {
+		return 0, err
+	}
+	diskSize := int64(st.F_bsize) * int64(st.F_blocks)
+	return diskSize, nil
+}

cmd/buildkitd/config/gcpolicy_unix.go

@@ -1,5 +1,5 @@
-//go:build !windows
-// +build !windows
+//go:build !windows && !openbsd
+// +build !windows,!openbsd
 
 package config