patman: Add -a option to refrain from test-applying the patches

Especially with the Linux kernel, it takes a long time (a minute or more)
to test-apply the patches, so patman becomes significantly less useful.
The only real problem that is found with this apply step is trailing spaces.
Provide a -a option to skip this step, for those working with clean patches.

Signed-off-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Doug Anderson <dianders@chromium.org>
diff --git a/tools/patman/patman.py b/tools/patman/patman.py
index 23026be..a8061a9 100755
--- a/tools/patman/patman.py
+++ b/tools/patman/patman.py
@@ -41,6 +41,9 @@
 
 
 parser = OptionParser()
+parser.add_option('-a', '--no-apply', action='store_false',
+                  dest='apply_patches', default=True,
+                  help="Don't test-apply patches with git am")
 parser.add_option('-H', '--full-help', action='store_true', dest='full_help',
        default=False, help='Display the README file')
 parser.add_option('-c', '--count', dest='count', type='int',
@@ -157,9 +160,10 @@
         ok = checkpatch.CheckPatches(options.verbose, args)
     else:
         ok = True
-    if not gitutil.ApplyPatches(options.verbose, args,
-            options.count + options.start):
-        ok = False
+    if options.apply_patches:
+        if not gitutil.ApplyPatches(options.verbose, args,
+                                    options.count + options.start):
+            ok = False
 
     cc_file = series.MakeCcFile(options.process_tags, cover_fname,
                                 not options.ignore_bad_tags)