Remove a few compiler warnings

Signed-off-by: Lars Hjemli <hjemli@gmail.com>

shared.c

@@ -308,7 +308,8 @@ static int load_mmfile(mmfile_t *file, const unsigned char *sha1)
 		file->ptr = (char *)"";
 		file->size = 0;
 	} else {
-		file->ptr = read_sha1_file(sha1, &type, &file->size);
+		file->ptr = read_sha1_file(sha1, &type, 
+		                           (unsigned long *)&file->size);
 	}
 	return 1;
 }

ui-tree.c

@@ -15,7 +15,7 @@ int header = 0;
 static void print_object(const unsigned char *sha1, char *path)
 {
 	enum object_type type;
-	unsigned char *buf;
+	char *buf;
 	unsigned long size, lineno, start, idx;
 	const char *linefmt = "<tr><td class='no'><a name='%1$d'>%1$d</a></td><td class='txt'>";