Check for ARCHIVE_FATAL should be in the while loop

It is impossible for if (r == ARCHIVE_FATAL) to be true otherwise, and it makes sense to check every time for a fatal error.

contrib/archivetest.c

@@ -201,7 +201,6 @@ int main(int argc, char *argv[])
 			v_print(v, "skipping");
 		} else {
 			while ((r = archive_read_data(a, buffer, 4096) > 0))
-			;
 			if (r == ARCHIVE_FATAL) {
 				v_print(v, "ERROR\nError string: %s\n",
 				    archive_error_string(a));