syscalls.bt: print syscall map every second

Signed-off-by: Jim Harris <james.r.harris@intel.com>
Change-Id: I3f1589880a00a0788fe5fbb2104789b3f81e1497
Reviewed-on: https://review.spdk.io/gerrit/c/spdk/spdk/+/10188
Community-CI: Broadcom CI <spdk-ci.pdl@broadcom.com>
Tested-by: SPDK CI Jenkins <sys_sgci@intel.com>
Reviewed-by: Changpeng Liu <changpeng.liu@intel.com>
Reviewed-by: Tomasz Zawadzki <tomasz.zawadzki@intel.com>

scripts/bpf/syscalls.bt

@@ -1,3 +1,9 @@
 tracepoint:syscalls:sys_enter_* /pid == __PID__/ {
 	@syscall[probe] = count();
 }
+
+interval:s:1 {
+	printf("\n");
+	print(@syscall);
+	clear(@syscall);
+}