Avoid returning random number while parsing route failed

In current code, while parsing route information from JSON failed.
The found will be 0, and the hyper_parse_routes will not be invoked.
In this case, the r_num will not be assigned and use a random value.

This will crash the guest kernel without the commit:
d43bd26b8562fe6c96ee762d96ceb65b9b6c067f

Change-Id: I2dd321b078d33bd1c3b2864ba81110eef17c8cb4
Signed-off-by: Wei Chen <Wei.Chen@arm.com>

Author: Weichen81

src/parse.c

@@ -1023,6 +1023,12 @@ int hyper_parse_setup_routes(struct hyper_route **routes, uint32_t *r_num, char
 	jsmntok_t *toks = NULL;
 	int found = 0;
 
+	/*
+	 * If we could not find routes from JSON, we have to set r_num to 0,
+	 * this will avid returning a random number for r_num.
+	 */
+	*r_num = 0;
+
 realloc:
 	toks = realloc(toks, toks_num * sizeof(jsmntok_t));
 	if (toks == NULL) {