buildman: run genboardscfg.py all the time

This commit makes sure boards.cfg is up to date before starting
the build tests.  tools/genboardscfg.py exits immediately printing
"boards.cfg is up to date. Nothing to do." when boards.cfg is
already new.

Signed-off-by: Masahiro Yamada <yamada.m@jp.panasonic.com>
Acked-by: Simon Glass <sjg@chromium.org>
diff --git a/tools/buildman/control.py b/tools/buildman/control.py
index d98e50a..68ea961 100644
--- a/tools/buildman/control.py
+++ b/tools/buildman/control.py
@@ -120,12 +120,10 @@
 
     # Work out what subset of the boards we are building
     board_file = os.path.join(options.git, 'boards.cfg')
-    if not os.path.exists(board_file):
-        print 'Could not find %s' % board_file
-        status = subprocess.call([os.path.join(options.git,
-                                               'tools/genboardscfg.py')])
-        if status != 0:
-            sys.exit("Failed to generate boards.cfg")
+    status = subprocess.call([os.path.join(options.git,
+                                           'tools/genboardscfg.py')])
+    if status != 0:
+        sys.exit("Failed to generate boards.cfg")
 
     boards = board.Boards()
     boards.ReadBoards(os.path.join(options.git, 'boards.cfg'))