wa: Remove reference to devlibs escaping methods

As part of https://github.com/ARM-software/devlib/pull/339 the escaping
method are being removed in favour of using `quote` from `pipes` so
also make reflecting changes here.

wa/commands/show.py

@@ -20,6 +20,7 @@
 
 import sys
 from subprocess import call, Popen, PIPE
+from pipes import quote
 
 from wa import Command
 from wa.framework import pluginloader
@@ -31,8 +32,6 @@ from wa.utils.doc import (strip_inlined_text, get_rst_from_plugin,
                           get_params_rst, underline)
 from wa.utils.misc import which
 
-from devlib.utils.misc import escape_double_quotes
-
 
 class ShowCommand(Command):
 
@@ -87,7 +86,7 @@ class ShowCommand(Command):
             title = '.TH {}{} 7'.format(kind, plugin_name)
             output = '\n'.join([title, body])
 
-            call('echo "{}" | man -l -'.format(escape_double_quotes(output)), shell=True)
+            call('echo {} | man -l -'.format(quote(output)), shell=True)
         else:
             print(rst_output)  # pylint: disable=superfluous-parens