Implement lock.Open() to fix #5642 (#6150)

pkg/lock/lock_solaris.go

@@ -98,3 +98,8 @@ func TryLockedOpenFile(path string, flag int, perm os.FileMode) (*LockedFile, er
 func LockedOpenFile(path string, flag int, perm os.FileMode) (*LockedFile, error) {
 	return lockedOpenFile(path, flag, perm, syscall.F_SETLKW)
 }
+
+// Open - Call os.OpenFile
+func Open(path string, flag int, perm os.FileMode) (*os.File, error) {
+	return os.OpenFile(path, flag, perm)
+}