Add cast to prevent sign-compare compiler warning
diff --git a/src/libusbmuxd.c b/src/libusbmuxd.c
index 23d549b..cfb34a2 100644
--- a/src/libusbmuxd.c
+++ b/src/libusbmuxd.c
@@ -701,11 +701,11 @@
size_t r = fread(tmpbuf, 1, 512, f);
if (r > 0) {
char *p = tmpbuf;
- while ((p-tmpbuf < r) && (*p != '(') && (*p != '\0')) p++;
+ while (((size_t)(p-tmpbuf) < r) && (*p != '(') && (*p != '\0')) p++;
if (*p == '(') {
p++;
char *pname = p;
- while ((p-tmpbuf < r) && (*p != ')') && (*p != '\0')) p++;
+ while (((size_t)(p-tmpbuf) < r) && (*p != ')') && (*p != '\0')) p++;
if (*p == ')') {
*p = '\0';
prog_name = strdup(pname);