Fix lutil_memrchr():

Avoid void* pointer arithmetic.
Convert int c to unsigned char, so c=<negative char value> will match.
Do not decrement pointer below start of array (even when value is not used).

libraries/liblutil/utils.c

@@ -311,22 +311,21 @@ int mkstemp( char * template )
 }
 #endif
 
-/* 
+/*
  * Memory Reverse Search
  */
 void *
-lutil_memrchr(const void *b, int c, size_t n) 
+lutil_memrchr(const void *b, int c, size_t n)
 {
 	if (n != 0) {
-		const unsigned char *s;
+		const unsigned char *s, *bb = b, cc = c;
 
-		for ( s = b + n; s-- > b; ) {
-			if ( *s == c ) {
-				return s;
+		for ( s = bb + n; s > bb; ) {
+			if ( *--s == cc ) {
+				return (void *) s;
 			}
 		}
 	}
 
 	return NULL;
-} 
-
+}