Fix a protocol botch: after returning SSH_MSG_USERAUTH_PK_OK to say
it's ok to proceed with publickey authentication, stay in Authing state
instead of switching to Established.  This was causing MacOSX ssh client
to hang.

Reference: /n/sources/patch/applied/ssh2-pk-ok
Date: Wed Jul 25 16:45:59 CES 2012
Signed-off-by: miller@hamnavoe.com

--- /sys/src/cmd/ssh2/netssh.c	Wed Jul 25 16:42:48 2012
+++ /sys/src/cmd/ssh2/netssh.c	Wed Jul 25 16:42:42 2012
@@ -2534,12 +2534,14 @@
 			bail(c, p, p2, "msg disconnect");
 		case SSH_MSG_USERAUTH_REQUEST:
 			switch (auth_req(p, c)) {
-			case 0:
+			case 0:		/* success */
 				establish(c);
 				break;
-			case -1:
+			case 1:		/* ok to try again */
 				break;
-			case -2:
+			case -1:	/* failure */
+				break;
+			case -2:	/* can't happen? */
 				bail(c, p, p2, "in userauth request");
 			}
 			break;
@@ -2892,7 +2894,7 @@
 		add_byte(p2, SSH_MSG_USERAUTH_PK_OK);
 		add_string(p2, alg);
 		add_block(p2, blob, nblob);
-		return 0;
+		return 1;
 	}
 
 	get_string(p, q, sig, Blobsz, &nsig);