binman: Convert to using the lz4 bintool

Update the code to use this bintool, instead of running lz4 directly. This
simplifies the code and provides more consistency.

Signed-off-by: Simon Glass <sjg@chromium.org>

tools/binman/cbfs_util_test.py

@@ -19,6 +19,7 @@ import unittest
 from binman import bintool
 from binman import cbfs_util
 from binman.cbfs_util import CbfsWriter
+from binman import comp_util
 from binman import elf
 from patman import test_util
 from patman import tools
@@ -49,12 +50,7 @@ class TestCbfs(unittest.TestCase):
         cls.cbfstool = bintool.Bintool.create('cbfstool')
         cls.have_cbfstool = cls.cbfstool.is_present()
 
-        cls.have_lz4 = True
-        try:
-            tools.Run('lz4', '--no-frame-crc', '-c',
-                      tools.GetInputFilename('u-boot.bin'), binary=True)
-        except:
-            cls.have_lz4 = False
+        cls.have_lz4 = comp_util.HAVE_LZ4
 
     @classmethod
     def tearDownClass(cls):