ip: Preserve original portocol family in batch mode

Reset the 'preferred_family' global variable
to its initially set value before each batch
file command is processed.

Signed-off-by: Antti Paila <antti.paila@gmail.com>

ip/ip.c

@@ -118,6 +118,7 @@ static int batch(const char *name)
 	char *line = NULL;
 	size_t len = 0;
 	int ret = EXIT_SUCCESS;
+	int orig_family = preferred_family;
 
 	batch_mode = 1;
 
@@ -140,6 +141,8 @@ static int batch(const char *name)
 		char *largv[100];
 		int largc;
 
+		preferred_family = orig_family;
+
 		largc = makeargs(line, largv, 100);
 		if (largc == 0)
 			continue;	/* blank line */