QA: Remove dry run mode

It didn't work as planned because some commands depend on the return
value or output of some operations.

Reviewed-by: iustinp

qa/ganeti-qa.py

@@ -237,9 +237,6 @@ def main():
 
   """
   parser = optparse.OptionParser(usage="%prog [options] <config-file>")
-  parser.add_option('--dry-run', dest='dry_run',
-      action="store_true",
-      help="Show what would be done")
   parser.add_option('--yes-do-it', dest='yes_do_it',
       action="store_true",
       help="Really execute the tests")

qa/qa_utils.py

@@ -111,13 +111,7 @@ def GetSSHCommand(node, cmd, strict=True):
   args.append('-oClearAllForwardings=yes')
   args.append('-oForwardAgent=yes')
   args.append(node)
-
-  if qa_config.options.dry_run:
-    prefix = 'exit 0; '
-  else:
-    prefix = ''
-
-  args.append(prefix + cmd)
+  args.append(cmd)
 
   print 'SSH:', utils.ShellQuoteArgs(args)