pthread/SDL_systhread.c: always include errno.h fixes build for several targets after commit 87b02d3 for bug #5283.
diff --git a/src/thread/pthread/SDL_systhread.c b/src/thread/pthread/SDL_systhread.c
index 75a03ab..3b3f40f 100644
--- a/src/thread/pthread/SDL_systhread.c
+++ b/src/thread/pthread/SDL_systhread.c
@@ -30,21 +30,17 @@
#endif
#include <signal.h>
+#include <errno.h>
#ifdef __LINUX__
#include <sys/time.h>
#include <sys/resource.h>
#include <sys/syscall.h>
#include <unistd.h>
-#include <errno.h>
#include "../../core/linux/SDL_dbus.h"
#endif /* __LINUX__ */
-#if __RISCOS__
-# include <errno.h>
-#endif
-
#if (defined(__LINUX__) || defined(__MACOSX__) || defined(__IPHONEOS__)) && defined(HAVE_DLOPEN)
#include <dlfcn.h>
#ifndef RTLD_DEFAULT