scripts/yocto-bsp: Fixed typo in parameter that was causing exception

There is a typo in the logging parameters, "filname" is being used instead
of "filename". This didn't cause issues before since python 2 didn't
validate unused parameters but with python >= 3.4.3 an exception is
thrown. This patch fixes this parameter name.

[Yocto #9736]

(From meta-yocto rev: aae5c2c39f64be87152b2e5470b50681c0f54670)

Signed-off-by: Humberto Ibarra <humberto.ibarra.lopez@intel.com>
Signed-off-by: Ross Burton <ross.burton@intel.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

scripts/yocto-bsp

@@ -118,7 +118,7 @@ subcommands = {
 
 
 def start_logging(loglevel):
-    logging.basicConfig(filname = 'yocto-bsp.log', filemode = 'w', level=loglevel)
+    logging.basicConfig(filename = 'yocto-bsp.log', filemode = 'w', level=loglevel)
 
 
 def main():