compat: drop unsupported ubuntu

These are unsupported by Canonical.

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

Author: zx2c4

src/compat/compat.h

@@ -28,10 +28,6 @@
 #define ISUBUNTU1604
 #elif LINUX_VERSION_CODE < KERNEL_VERSION(4, 16, 0) && LINUX_VERSION_CODE >= KERNEL_VERSION(4, 15, 0)
 #define ISUBUNTU1804
-#elif LINUX_VERSION_CODE < KERNEL_VERSION(5, 1, 0) && LINUX_VERSION_CODE >= KERNEL_VERSION(5, 0, 0)
-#define ISUBUNTU1904
-#elif LINUX_VERSION_CODE < KERNEL_VERSION(5, 4, 0) && LINUX_VERSION_CODE >= KERNEL_VERSION(5, 3, 0)
-#define ISUBUNTU1910
 #endif
 #endif
 
@@ -91,7 +87,7 @@
 
 #if LINUX_VERSION_CODE < KERNEL_VERSION(3, 17, 0) && LINUX_VERSION_CODE >= KERNEL_VERSION(3, 16, 83)
 #define ipv6_dst_lookup_flow(a, b, c, d) ipv6_dst_lookup_flow(b, c, d)
-#elif (LINUX_VERSION_CODE < KERNEL_VERSION(5, 4, 5) && LINUX_VERSION_CODE >= KERNEL_VERSION(5, 4, 0)) || (LINUX_VERSION_CODE < KERNEL_VERSION(5, 3, 18) && LINUX_VERSION_CODE >= KERNEL_VERSION(4, 20, 0) && !defined(ISUBUNTU1904)) || (!defined(ISRHEL8) && !defined(ISDEBIAN) && !defined(ISUBUNTU1804) && LINUX_VERSION_CODE < KERNEL_VERSION(4, 19, 119) && LINUX_VERSION_CODE >= KERNEL_VERSION(4, 15, 0)) || (LINUX_VERSION_CODE < KERNEL_VERSION(4, 14, 181) && LINUX_VERSION_CODE >= KERNEL_VERSION(4, 10, 0)) || (LINUX_VERSION_CODE < KERNEL_VERSION(4, 9, 224) && LINUX_VERSION_CODE >= KERNEL_VERSION(4, 5, 0)) || (LINUX_VERSION_CODE < KERNEL_VERSION(4, 4, 224) && !defined(ISUBUNTU1604) && !defined(ISRHEL7))
+#elif (LINUX_VERSION_CODE < KERNEL_VERSION(5, 4, 5) && LINUX_VERSION_CODE >= KERNEL_VERSION(5, 4, 0)) || (LINUX_VERSION_CODE < KERNEL_VERSION(5, 3, 18) && LINUX_VERSION_CODE >= KERNEL_VERSION(4, 20, 0)) || (!defined(ISRHEL8) && !defined(ISDEBIAN) && !defined(ISUBUNTU1804) && LINUX_VERSION_CODE < KERNEL_VERSION(4, 19, 119) && LINUX_VERSION_CODE >= KERNEL_VERSION(4, 15, 0)) || (LINUX_VERSION_CODE < KERNEL_VERSION(4, 14, 181) && LINUX_VERSION_CODE >= KERNEL_VERSION(4, 10, 0)) || (LINUX_VERSION_CODE < KERNEL_VERSION(4, 9, 224) && LINUX_VERSION_CODE >= KERNEL_VERSION(4, 5, 0)) || (LINUX_VERSION_CODE < KERNEL_VERSION(4, 4, 224) && !defined(ISUBUNTU1604) && !defined(ISRHEL7))
 #define ipv6_dst_lookup_flow(a, b, c, d) ipv6_dst_lookup(a, b, &dst, c) + (void *)0 ?: dst
 #endif
 
@@ -1024,7 +1020,7 @@ static inline void __compat_icmpv6_ndo_send(struct sk_buff *skb_in, u8 type, u8
 #define COMPAT_CANNOT_USE_MAX_MTU
 #endif
 
-#if (LINUX_VERSION_CODE < KERNEL_VERSION(5, 5, 14) && LINUX_VERSION_CODE >= KERNEL_VERSION(5, 5, 0)) || (LINUX_VERSION_CODE < KERNEL_VERSION(5, 4, 29) && !defined(ISUBUNTU1910) && !defined(ISUBUNTU1904) && !defined(ISRHEL8))
+#if (LINUX_VERSION_CODE < KERNEL_VERSION(5, 5, 14) && LINUX_VERSION_CODE >= KERNEL_VERSION(5, 5, 0)) || (LINUX_VERSION_CODE < KERNEL_VERSION(5, 4, 29) && !defined(ISRHEL8))
 #include <linux/skbuff.h>
 #include <net/sch_generic.h>
 static inline void skb_reset_redirect(struct sk_buff *skb)