Because the argument to strvalid() is a size_t, use a size_t to iterate

over the array.

Submitted by:	stefanf

sys/libkern/strvalid.c

@@ -42,7 +42,7 @@ __FBSDID("$FreeBSD$");
 int
 strvalid(const char *buffer, size_t bufferlen)
 {
-	int i;
+	size_t i;
 
 	/* Must be NUL-terminated. */
 	for (i = 0; i < bufferlen; i++)