monitor: fix file handle leak

In some cases passing file to monitor left file open.
Signed-off-by: Stephen Hemminger <stephen@networkplumber.org>

ip/ipmonitor.c

@@ -284,12 +284,16 @@ int do_ipmonitor(int argc, char **argv)
 	}
 	if (file) {
 		FILE *fp;
+		int err;
+
 		fp = fopen(file, "r");
 		if (fp == NULL) {
 			perror("Cannot fopen");
 			exit(-1);
 		}
-		return rtnl_from_file(fp, accept_msg, stdout);
+		err = rtnl_from_file(fp, accept_msg, stdout);
+		fclose(fp);
+		return err;
 	}
 
 	if (rtnl_open(&rth, groups) < 0)

ip/xfrm_monitor.c

@@ -411,12 +411,16 @@ int do_xfrm_monitor(int argc, char **argv)
 
 	if (file) {
 		FILE *fp;
+		int err;
+
 		fp = fopen(file, "r");
 		if (fp == NULL) {
 			perror("Cannot fopen");
 			exit(-1);
 		}
-		return rtnl_from_file(fp, xfrm_accept_msg, (void*)stdout);
+		err = rtnl_from_file(fp, xfrm_accept_msg, stdout);
+		fclose(fp);
+		return err;
 	}
 
 	if (rtnl_open_byproto(&rth, groups, NETLINK_XFRM) < 0)

tc/tc_monitor.c

@@ -91,13 +91,17 @@ int do_tcmonitor(int argc, char **argv)
 	}
 
 	if (file) {
-		FILE *fp;
-		fp = fopen(file, "r");
+		FILE *fp = fopen(file, "r");
+		int ret;
+
 		if (fp == NULL) {
 			perror("Cannot fopen");
 			exit(-1);
 		}
-		return rtnl_from_file(fp, accept_tcmsg, (void*)stdout);
+
+		ret = rtnl_from_file(fp, accept_tcmsg, stdout);
+		fclose(fp);
+		return ret;
 	}
 
 	if (rtnl_open(&rth, groups) < 0)