fix sigorset/sigandset: _NSIG/8 is the size in bytes

src/signal/sigandset.c

 #define _GNU_SOURCE
 #include <signal.h>
 
-#define SST_SIZE (_NSIG/8)
+#define SST_SIZE (_NSIG/8/sizeof(long))
 
 int sigandset(sigset_t *dest, sigset_t *left, sigset_t *right)
 {

src/signal/sigorset.c

 #define _GNU_SOURCE
 #include <signal.h>
 
-#define SST_SIZE (_NSIG/8)
+#define SST_SIZE (_NSIG/8/sizeof(long))
 
 int sigorset(sigset_t *dest, sigset_t *left, sigset_t *right)
 {