install-buildtools: remove md5 checksum validation

No need to validate with the md5 checksum, as the file is not even
uploaded to the Yocto release webpage (the download never failed due
to a wrong indentation of an else statement). For validation purposes,
use the sha256 checksum only.

(From OE-Core rev: b331769084996ffeb74007fe6ca7e385edd7a577)

Signed-off-by: Aleksandar Nikolic <aleksandar.nikolic@zeiss.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>
(cherry picked from commit b740d2f9d40aef1e18c022d1e82b4fb2c5c1fc22)
Signed-off-by: Aleksandar Nikolic <aleksandar.nikolic@zeiss.com>
Signed-off-by: Steve Sakoman <steve@sakoman.com>

scripts/install-buildtools

@@ -238,19 +238,15 @@ def main():
         # Verify checksum
         if args.check:
             logger.info("Fetching buildtools installer checksum")
-            checksum_type = ""
-            for checksum_type in ["md5sum", "sha256sum"]:
-                check_url = "{}.{}".format(buildtools_url, checksum_type)
-                checksum_filename = "{}.{}".format(filename, checksum_type)
-                tmpbuildtools_checksum = os.path.join(tmpsdk_dir, checksum_filename)
-                ret = subprocess.call("wget -q -O %s %s" %
-                                      (tmpbuildtools_checksum, check_url), shell=True)
-                if ret == 0:
-                    break
-            else:
-                if ret != 0:
-                    logger.error("Could not download file from %s" % check_url)
-                    return ret
+            checksum_type = "sha256sum"
+            check_url = "{}.{}".format(buildtools_url, checksum_type)
+            checksum_filename = "{}.{}".format(filename, checksum_type)
+            tmpbuildtools_checksum = os.path.join(tmpsdk_dir, checksum_filename)
+            ret = subprocess.call("wget -q -O %s %s" %
+                                    (tmpbuildtools_checksum, check_url), shell=True)
+            if ret != 0:
+                logger.error("Could not download file from %s" % check_url)
+                return ret
             regex = re.compile(r"^(?P<checksum>[0-9a-f]+)\s+(?P<path>.*/)?(?P<filename>.*)$")
             with open(tmpbuildtools_checksum, 'rb') as f:
                 original = f.read()
@@ -263,10 +259,7 @@ def main():
                     logger.error("Filename does not match name in checksum")
                     return 1
                 checksum = m.group('checksum')
-            if checksum_type == "md5sum":
-                checksum_value = md5_file(tmpbuildtools)
-            else:
-                checksum_value = sha256_file(tmpbuildtools)
+            checksum_value = sha256_file(tmpbuildtools)
             if checksum == checksum_value:
                     logger.info("Checksum success")
             else: