tools: acrn-manager: fix warnings before updating Makefile

- Print warning if string truncated to avoid the warning generated
  by -Wformat-truncation by GCC 7.0 and newer version;
- fixed strncpy size.

Tracked-On: #1122
Signed-off-by: Yan, Like <like.yan@intel.com>
Acked-by: Eddie Dong <eddie.dong@intel.com>

tools/acrn-manager/acrnd.c

@@ -175,7 +175,7 @@ static int load_timer_list(void)
 		}
 
 		memset(arg.name, 0, sizeof(arg.name));
-		strncpy(arg.name, s1, sizeof(s1));
+		strncpy(arg.name, s1, sizeof(arg.name));
 
 		expire = strtoul(s2, NULL, 10);
 		if (expire == 0 || errno == ERANGE) {