Revert "selftests: kselftest: Fix build failure with NOLIBC"

This reverts commit 1676750.

Nolibc gained support for uname(2) and sscanf(3) which are the
dependencies of ksft_min_kernel_version().

So re-enable support for ksft_min_kernel_version() under nolibc.

Acked-by: Shuah Khan <skhan@linuxfoundation.org>
Acked-by: Willy Tarreau <w@1wt.eu>
Link: https://lore.kernel.org/r/20250209-nolibc-scanf-v2-2-c29dea32f1cd@weissschuh.net
Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>

Author: t-8ch

tools/testing/selftests/kselftest.h

@@ -444,18 +444,13 @@ static inline __noreturn __printf(1, 2) void ksft_exit_skip(const char *msg, ...
 static inline int ksft_min_kernel_version(unsigned int min_major,
 					  unsigned int min_minor)
 {
-#ifdef NOLIBC
-	ksft_print_msg("NOLIBC: Can't check kernel version: Function not implemented\n");
-	return 0;
-#else
 	unsigned int major, minor;
 	struct utsname info;
 
 	if (uname(&info) || sscanf(info.release, "%u.%u.", &major, &minor) != 2)
 		ksft_exit_fail_msg("Can't parse kernel version\n");
 
 	return major > min_major || (major == min_major && minor >= min_minor);
-#endif
 }
 
 #endif /* __KSELFTEST_H */