[FL-1530] Cli: better Сtrl-С polling (#586)

applications/cli/cli.c

@@ -57,8 +57,11 @@ size_t cli_read(Cli* cli, uint8_t* buffer, size_t size) {
 
 bool cli_cmd_interrupt_received(Cli* cli) {
     char c = '\0';
-    api_hal_vcp_rx_with_timeout((uint8_t*)&c, 1, 1);
-    return c == CliSymbolAsciiETX;
+    if(api_hal_vcp_rx_with_timeout((uint8_t*)&c, 1, 0) == 1) {
+        return c == CliSymbolAsciiETX;
+    } else {
+        return false;
+    }
 }
 
 void cli_print_usage(const char* cmd, const char* usage, const char* arg) {