compat: account for latest c8s backports

Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>

Author: zx2c4

src/compat/compat.h

@@ -16,7 +16,7 @@
 #define ISRHEL7
 #elif RHEL_MAJOR == 8
 #define ISRHEL8
-#if RHEL_MINOR >= 4
+#if RHEL_MINOR >= 5
 #define ISCENTOS8S
 #endif
 #endif
@@ -757,7 +757,7 @@ static inline void crypto_xor_cpy(u8 *dst, const u8 *src1, const u8 *src2,
 #define hlist_add_behind(a, b) hlist_add_after(b, a)
 #endif
 
-#if LINUX_VERSION_CODE < KERNEL_VERSION(5, 0, 0) && !defined(ISCENTOS8S)
+#if LINUX_VERSION_CODE < KERNEL_VERSION(5, 0, 0) && !defined(ISRHEL8)
 #define totalram_pages() totalram_pages
 #endif
 
@@ -849,7 +849,7 @@ static inline void skb_mark_not_on_list(struct sk_buff *skb)
 #endif
 #endif
 
-#if LINUX_VERSION_CODE < KERNEL_VERSION(5, 5, 0)
+#if LINUX_VERSION_CODE < KERNEL_VERSION(5, 5, 0) && !defined(ISCENTOS8S)
 #define genl_dumpit_info(cb) ({ \
 	struct { struct nlattr **attrs; } *a = (void *)((u8 *)cb->args + offsetofend(struct dump_ctx, next_allowedip)); \
 	BUILD_BUG_ON(sizeof(cb->args) < offsetofend(struct dump_ctx, next_allowedip) + sizeof(*a)); \