Revert "fix tst-signal7 failure"

This reverts commit ea21c7610aa1131b37a4533cf13dd89f727fb83f.

This was accidently pushed, before first coffee.
Sorry this is a bad commit.

libc/signal/sigaction.c

@@ -25,11 +25,6 @@
 int
 __libc_sigaction(int sig, const struct sigaction *act, struct sigaction *oact)
 {
-	if (unlikely (sig == SIGCANCEL || sig == SIGSETXID)) {
-		__set_errno (EINVAL);
-		return -1;
-	}
-
 	/* NB: kernel (as of 2.6.25) will return EINVAL
 	 * if sizeof(act->sa_mask) does not match kernel's sizeof(sigset_t).
 	 * Try to catch this problem at uclibc build time:  */
@@ -53,11 +48,6 @@ __libc_sigaction(int sig, const struct sigaction *act, struct sigaction *oact)
 	int result;
 	struct old_kernel_sigaction kact, koact;
 
-	if (unlikely (sig == SIGCANCEL || sig == SIGSETXID)) {
-		__set_errno (EINVAL);
-		return -1;
-	}
-
 	if (act) {
 		kact.k_sa_handler = act->sa_handler;
 		kact.sa_mask = act->sa_mask.__val[0];