split time setting from gid setting via wstat.

Reference: /n/sources/patch/applied/tar-2-wstats
Date: Sun Mar 12 01:26:46 CET 2006
Signed-off-by: geoff@collyer.net

--- /sys/src/cmd/tar.c	Sun Mar 12 01:26:26 2006
+++ /sys/src/cmd/tar.c	Sun Mar 12 01:26:11 2006
@@ -1027,9 +1027,12 @@
 
 			nulldir(&nd);
 			nd.mtime = mtime;
-			if (isustar(hp))
-				nd.gid = hp->gname;
 			dirfwstat(fd, &nd);
+			if (isustar(hp)) {
+				nulldir(&nd);
+				nd.gid = hp->gname;
+				dirfwstat(fd, &nd);
+			}
 		}
 		close(fd);
 	}
@@ -1168,4 +1171,4 @@
 		break;
 	}
 	exits(ret);
-}
+}