[PATCH] selftests/rseq: Replace glibc-specific __GNUC_PREREQ with portable check

[Hisam Mehboob <hisamshar@gmail.com>]

Building the rseq selftests against musl libc fails because musl's
<features.h> does not provide the glibc-specific __GNUC_PREREQ macro:

  error: missing binary operator before token '('

Replace __GNUC_PREREQ(11, 1) with an equivalent check using __GNUC__
and __GNUC_MINOR__ directly.  This pattern is portable across all C
library implementations and is already used elsewhere in the tools/
tree (e.g., tools/include/linux/string.h).

This also allows removing the #include <features.h>, which was only
needed for __GNUC_PREREQ.

Fixes: 886ddfba933f ("selftests/rseq: Introduce thread pointer getters")
Signed-off-by: Hisam Mehboob <hisamshar@gmail.com>
---
 tools/testing/selftests/rseq/rseq-x86-thread-pointer.h | 4 +---
 1 file changed, 1 insertion(+), 3 deletions(-)

diff --git a/tools/testing/selftests/rseq/rseq-x86-thread-pointer.h b/tools/testing/selftests/rseq/rseq-x86-thread-pointer.h
index d3133587d996..5a29d6bec51f 100644
--- a/tools/testing/selftests/rseq/rseq-x86-thread-pointer.h
+++ b/tools/testing/selftests/rseq/rseq-x86-thread-pointer.h
@@ -8,13 +8,11 @@
 #ifndef _RSEQ_X86_THREAD_POINTER
 #define _RSEQ_X86_THREAD_POINTER
 
-#include <features.h>
-
 #ifdef __cplusplus
 extern "C" {
 #endif
 
-#if __GNUC_PREREQ (11, 1)
+#if __GNUC__ > 11 || (__GNUC__ == 11 && __GNUC_MINOR__ >= 1)
 static inline void *rseq_thread_pointer(void)
 {
 	return __builtin_thread_pointer();
-- 
2.51.0