[FAB-7675] fix make verify

The refactor done in FAB-7649 inverted the match for go files in the
packages_diff function. This corrects the behavior and removes an
unnecessary local variable.

Change-Id: I4aba1aef7fb0775f8b73484c1960c41e01ba3967
Signed-off-by: Matthew Sykes <sykesmat@us.ibm.com>

Author: sykesm

unit-test/run.sh

@@ -34,10 +34,8 @@ serial_packages=(
 
 # obtain packages changed since some git refspec
 packages_diff() {
-    local ref="${1:-HEAD}"
-
     git -C "${GOPATH}/src/github.com/hyperledger/fabric" diff --no-commit-id --name-only -r "${1:-HEAD}" |
-        grep -Ev '.go$|^vendor/|^build/' | \
+        grep '.go$' | grep -Ev '^vendor/|^build/' | \
         sed 's%/[^/]*$%/%' | sort -u | \
         awk '{print "github.com/hyperledger/fabric/"$1"..."}'
 }