unix/unix_mphal: Just consistently set sigaction.sa_flags to 0.

unix/unix_mphal.c

@@ -53,7 +53,7 @@ void mp_hal_set_interrupt_char(char c) {
         #ifndef _WIN32
         // enable signal handler
         struct sigaction sa;
-        memset(&sa, 0, sizeof(sa));
+        sa.sa_flags = 0;
         sa.sa_handler = sighandler;
         sigemptyset(&sa.sa_mask);
         sigaction(SIGINT, &sa, NULL);
@@ -62,6 +62,7 @@ void mp_hal_set_interrupt_char(char c) {
         #ifndef _WIN32
         // disable signal handler
         struct sigaction sa;
+        sa.sa_flags = 0;
         sa.sa_handler = SIG_DFL;
         sigemptyset(&sa.sa_mask);
         sigaction(SIGINT, &sa, NULL);