tar: revert older fix (non-portable), added new one.
     testsuite tar-extracts-all-subdirs now passes.

diff --git a/archival/tar.c b/archival/tar.c
index 160731e..0b5720f 100644
--- a/archival/tar.c
+++ b/archival/tar.c
@@ -545,8 +545,12 @@
 		tmp = cur;
 		cur = cur->link;
 		free(tmp);
-		while ((line = bb_get_chomped_line_from_file(src_stream)) != NULL)
+		while ((line = bb_get_chomped_line_from_file(src_stream)) != NULL) {
+				char *filename_ptr = last_char_is(line, '/');
+				if (filename_ptr > line)
+					*filename_ptr = '\0';
 				llist_add_to(&newlist, line);
+		}
 		fclose(src_stream);
 	}
 	return newlist;