Update Linux to v5.4.2

Change-Id: Idf6911045d9d382da2cfe01b1edff026404ac8fd
diff --git a/scripts/setlocalversion b/scripts/setlocalversion
index 71f3941..a2998b1 100755
--- a/scripts/setlocalversion
+++ b/scripts/setlocalversion
@@ -73,8 +73,16 @@
 			printf -- '-svn%s' "`git svn find-rev $head`"
 		fi
 
-		# Check for uncommitted changes
-		if git diff-index --name-only HEAD | grep -qv "^scripts/package"; then
+		# Check for uncommitted changes.
+		# First, with git-status, but --no-optional-locks is only
+		# supported in git >= 2.14, so fall back to git-diff-index if
+		# it fails. Note that git-diff-index does not refresh the
+		# index, so it may give misleading results. See
+		# git-update-index(1), git-diff-index(1), and git-status(1).
+		if {
+			git --no-optional-locks status -uno --porcelain 2>/dev/null ||
+			git diff-index --name-only HEAD
+		} | grep -qvE '^(.. )?scripts/package'; then
 			printf '%s' -dirty
 		fi
 
@@ -85,7 +93,7 @@
 	# Check for mercurial and a mercurial repo.
 	if test -d .hg && hgid=`hg id 2>/dev/null`; then
 		# Do we have an tagged version?  If so, latesttagdistance == 1
-		if [ "`hg log -r . --template '{latesttagdistance}'`" == "1" ]; then
+		if [ "`hg log -r . --template '{latesttagdistance}'`" = "1" ]; then
 			id=`hg log -r . --template '{latesttag}'`
 			printf '%s%s' -hg "$id"
 		else
@@ -118,7 +126,7 @@
 
 collect_files()
 {
-	local file res
+	local file res=
 
 	for file; do
 		case "$file" in