Rename _ssh_sock() to fix code style issue.

Since _ssh_sock is imported out of the git_command module, the leading
underscore should be removed from the function name.
diff --git a/git_command.py b/git_command.py
index d56ad0a..3309f37 100644
--- a/git_command.py
+++ b/git_command.py
@@ -30,7 +30,7 @@
 _ssh_proxy_path = None
 _ssh_sock_path = None
 
-def _ssh_sock(create=True):
+def ssh_sock(create=True):
   global _ssh_sock_path
   if _ssh_sock_path is None:
     if not create:
@@ -119,7 +119,7 @@
     if disable_editor:
       env['GIT_EDITOR'] = ':'
     if ssh_proxy:
-      env['REPO_SSH_SOCK'] = _ssh_sock()
+      env['REPO_SSH_SOCK'] = ssh_sock()
       env['GIT_SSH'] = _ssh_proxy()
 
     if project:
diff --git a/git_config.py b/git_config.py
index 45a2d25..a7c8210 100644
--- a/git_config.py
+++ b/git_config.py
@@ -23,7 +23,7 @@
 from urllib2 import urlopen, HTTPError
 from error import GitError, UploadError
 from trace import Trace
-from git_command import GitCommand, _ssh_sock
+from git_command import GitCommand, ssh_sock
 
 R_HEADS = 'refs/heads/'
 R_TAGS  = 'refs/tags/'
@@ -371,7 +371,7 @@
     return False
 
   command = ['ssh',
-             '-o','ControlPath %s' % _ssh_sock(),
+             '-o','ControlPath %s' % ssh_sock(),
              '-p',str(port),
              '-M',
              '-N',
@@ -399,7 +399,7 @@
       pass
   _ssh_cache.clear()
 
-  d = _ssh_sock(create=False)
+  d = ssh_sock(create=False)
   if d:
     try:
       os.rmdir(os.path.dirname(d))