json-c: merge an upstream fix for a compiler warning (fixes #19187)

Signed-off-by: Felix Fietkau <nbd@openwrt.org>

SVN-Revision: 44826

package/libs/libjson-c/patches/001-backport_compile_fix.patch

@@ -0,0 +1,23 @@
+commit 3859e99f50abe11a8dade28efa9ea3d99dfaac11
+Author: Petar Koretić <petar.koretic@gmail.com>
+Date:   Fri Apr 11 10:03:40 2014 +0200
+
+    Remove unused variable 'size'
+
+diff --git a/json_tokener.c b/json_tokener.c
+index 19de8ef..9a76293 100644
+--- a/json_tokener.c
++++ b/json_tokener.c
+@@ -352,12 +352,10 @@ struct json_object* json_tokener_parse_ex(struct json_tokener *tok,
+ 
+     case json_tokener_state_inf: /* aka starts with 'i' */
+       {
+-	int size;
+ 	int size_inf;
+ 	int is_negative = 0;
+ 
+ 	printbuf_memappend_fast(tok->pb, &c, 1);
+-	size = json_min(tok->st_pos+1, json_null_str_len);
+ 	size_inf = json_min(tok->st_pos+1, json_inf_str_len);
+ 	char *infbuf = tok->pb->buf;
+ 	if (*infbuf == '-')