selftests/x86/xstate: Fix spelling mistake "hader" -> "header"

There is a spelling mistake in a sig_print() message. Fix it.

Signed-off-by: Colin Ian King <colin.i.king@gmail.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lore.kernel.org/r/20250227091533.599213-1-colin.i.king@gmail.com

tools/testing/selftests/x86/xstate.c

@@ -391,7 +391,7 @@ static void validate_sigfpstate(int sig, siginfo_t *si, void *ctx_void)
 	if (get_xstatebv(xbuf) & xstate.mask)
 		sig_print("[OK]\t'xfeatures' in XSAVE header is valid\n");
 	else
-		sig_print("[FAIL]\t'xfeatures' in XSAVE hader is not valid\n");
+		sig_print("[FAIL]\t'xfeatures' in XSAVE header is not valid\n");
 
 	if (validate_xstate_same(stashed_xbuf, xbuf))
 		sig_print("[OK]\txstate delivery was successful\n");