scripts: Do not write out implcit $_ in foreach loops

Addresses Variables::RequireLexicalLoopIterators.

Warned-by: perlcritic

scripts/dpkg-genchanges.pl

@@ -269,7 +269,7 @@ if (not is_sourceonly) {
 
 # Scan control info of source package
 my $src_fields = $control->get_source();
-foreach $_ (keys %{$src_fields}) {
+foreach (keys %{$src_fields}) {
     my $v = $src_fields->{$_};
     if (m/^Source$/) {
 	set_source_package($v);
@@ -310,7 +310,7 @@ foreach my $pkg ($control->get_packages()) {
 
     $p2arch{$p} = $a;
 
-    foreach $_ (keys %{$pkg}) {
+    foreach (keys %{$pkg}) {
 	my $v = $pkg->{$_};
 
 	if (m/^Section$/) {
@@ -334,7 +334,7 @@ foreach my $pkg ($control->get_packages()) {
 }
 
 # Scan fields of dpkg-parsechangelog
-foreach $_ (keys %{$changelog}) {
+foreach (keys %{$changelog}) {
     my $v = $changelog->{$_};
     if (m/^Source$/i) {
 	set_source_package($v);

scripts/dpkg-gencontrol.pl

@@ -183,7 +183,7 @@ $substvars->set_msg_prefix(sprintf(_g('package %s: '), $pkg->{Package}));
 
 # Scan source package
 my $src_fields = $control->get_source();
-foreach $_ (keys %{$src_fields}) {
+foreach (keys %{$src_fields}) {
     if (m/^Source$/) {
 	set_source_package($src_fields->{$_});
     } else {
@@ -192,7 +192,7 @@ foreach $_ (keys %{$src_fields}) {
 }
 
 # Scan binary package
-foreach $_ (keys %{$pkg}) {
+foreach (keys %{$pkg}) {
     my $v = $pkg->{$_};
     if (field_get_dep_type($_)) {
 	# Delay the parsing until later
@@ -221,7 +221,7 @@ foreach $_ (keys %{$pkg}) {
 }
 
 # Scan fields of dpkg-parsechangelog
-foreach $_ (keys %{$changelog}) {
+foreach (keys %{$changelog}) {
     my $v = $changelog->{$_};
 
     if (m/^Source$/) {

scripts/dpkg-source.pl

@@ -238,7 +238,7 @@ if ($options{opmode} =~ /^(-b|--print-format|--(before|after)-build|--commit)$/)
           $controlfile) unless defined $src_fields;
     my $src_sect = $src_fields->{'Section'} || 'unknown';
     my $src_prio = $src_fields->{'Priority'} || 'unknown';
-    foreach $_ (keys %{$src_fields}) {
+    foreach (keys %{$src_fields}) {
 	my $v = $src_fields->{$_};
 	if (m/^Source$/i) {
 	    set_source_package($v);
@@ -269,7 +269,7 @@ if ($options{opmode} =~ /^(-b|--print-format|--(before|after)-build|--commit)$/)
 	        $pkg->get_custom_field('Package-Type') || 'deb';
 	push @pkglist, sprintf('%s %s %s %s', $p, $type, $sect, $prio);
 	push(@binarypackages,$p);
-	foreach $_ (keys %{$pkg}) {
+	foreach (keys %{$pkg}) {
 	    my $v = $pkg->{$_};
             if (m/^Architecture$/) {
                 # Gather all binary architectures in one set. 'any' and 'all'
@@ -322,7 +322,7 @@ if ($options{opmode} =~ /^(-b|--print-format|--(before|after)-build|--commit)$/)
     $fields->{'Package-List'} = "\n" . join("\n", sort @pkglist);
 
     # Scan fields of dpkg-parsechangelog
-    foreach $_ (keys %{$changelog}) {
+    foreach (keys %{$changelog}) {
         my $v = $changelog->{$_};
 
 	if (m/^Source$/) {