remove legacy VxWorks workaround

The same workaround was already removed in sockets.h
in 5c8b7b4caa0faedb69277063a7c6b3a8e56c6308

Reviewed-by: Paul Dale <pauli@openssl.org>
Reviewed-by: Tomas Mraz <tomas@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/18260)
diff --git a/crypto/rand/rand_egd.c b/crypto/rand/rand_egd.c
index b4e5ca3..acb1165 100644
--- a/crypto/rand/rand_egd.c
+++ b/crypto/rand/rand_egd.c
@@ -40,11 +40,7 @@
 # include <sys/types.h>
 # include <sys/socket.h>
 # ifndef NO_SYS_UN_H
-#  ifdef OPENSSL_SYS_VXWORKS
-#   include <streams/un.h>
-#  else
-#   include <sys/un.h>
-#  endif
+#  include <sys/un.h>
 # else
 struct sockaddr_un {
     short sun_family;           /* AF_UNIX */