scripts/check_format: prefer pycodestyle over pep8

pep8 has been renamed to pycodestyle; check for pycodestyle first so
that we prefer the up-to-date version over the deprecated pep8 name.

Change-Id: Ie9cf2d0c156885893926358cfb546432ad38f23d
Signed-off-by: Daniel Verkamp <daniel.verkamp@intel.com>
Reviewed-on: https://review.gerrithub.io/416760
Tested-by: SPDK Automated Test System <sys_sgsw@intel.com>
Reviewed-by: Ben Walker <benjamin.walker@intel.com>

scripts/check_format.sh

@@ -110,12 +110,10 @@ else
 fi
 rm -f scripts/posix.log
 
-if hash pep8 2>/dev/null; then
-	PEP8=pep8
-fi
-
 if hash pycodestyle 2>/dev/null; then
 	PEP8=pycodestyle
+elif hash pep8 2>/dev/null; then
+	PEP8=pep8
 fi
 
 if [ ! -z ${PEP8} ]; then