Revert "sigsetmask.c was not processing the "mask" argument."

This reverts commit 9a9c1619b8124f07fc772c0b700e4d411cd78525.
diff --git a/libc/unistd/sigsetmask.c b/libc/unistd/sigsetmask.c
index 4f46458..b987595 100644
--- a/libc/unistd/sigsetmask.c
+++ b/libc/unistd/sigsetmask.c
@@ -38,8 +38,6 @@
         sigset_t  the_sigset;
     } in, out;
 
-    in.the_mask = mask;
-
     n = sigprocmask(SIG_SETMASK, &in.the_sigset, &out.the_sigset);
     if (n)
         return n;