Revert "[openssh] Move control socket to ~/.ssh"

This reverts commit 8e2a43479e1c9ce60743cc6648599c2d652f21aa.

Reason for revert: breaks fx shell; see Fuchsia chat

Original change's description:
> [openssh] Move control socket to ~/.ssh
> 
> Change-Id: Iaf7dc9f5051639ad527226ce5b638d4caf3ea5e5
> Reviewed-on: https://fuchsia-review.googlesource.com/c/third_party/openssh-portable/+/427148
> Commit-Queue: Wesley Moy <wesleymoy@google.com>
> Reviewed-by: James Tucker <raggi@google.com>

TBR=raggi@google.com,mangini@google.com,wesleymoy@google.com

Change-Id: Ieb1b91d3bd9cea5cd2126fa2f453de1b7ccf373f
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Reviewed-on: https://fuchsia-review.googlesource.com/c/third_party/openssh-portable/+/429974
Reviewed-by: Wesley Moy <wesleymoy@google.com>
Commit-Queue: Wesley Moy <wesleymoy@google.com>
diff --git a/fuchsia/developer-keys/generate_ssh_config.sh b/fuchsia/developer-keys/generate_ssh_config.sh
index b17e8d9..c9eadcd 100755
--- a/fuchsia/developer-keys/generate_ssh_config.sh
+++ b/fuchsia/developer-keys/generate_ssh_config.sh
@@ -16,7 +16,7 @@
   IdentityFile $1
   ControlPersist yes
   ControlMaster auto
-  ControlPath ~/.ssh/fuchsia--%r@%h:%p
+  ControlPath /tmp/fuchsia-$USER-%r@%h:%p
   ConnectTimeout 10
   ServerAliveInterval 1
   ServerAliveCountMax 10