Merge pull request #167 from linD026/minmax

Improve the compatibility with kernel < v5.10

examples/procfs3.c

@@ -8,7 +8,9 @@
 #include <linux/sched.h>
 #include <linux/uaccess.h>
 #include <linux/version.h>
+#if LINUX_VERSION_CODE >= KERNEL_VERSION(5, 10, 0)
 #include <linux/minmax.h>
+#endif
 
 #if LINUX_VERSION_CODE >= KERNEL_VERSION(5, 6, 0)
 #define HAVE_PROC_OPS