checkpatch: make git output use LANGUAGE=en_US.utf8

git output parsing depends on the language being en_US english.

Make the backtick execution of all `git <foo>` commands set the
LANGUAGE of the process to en_US.utf8 before executing the actual
command using `export LANGUAGE=en_US.utf8; git <foo>`.

Because the command is executed in a child process, the parent
LANGUAGE is unchanged.

Link: http://lkml.kernel.org/r/bb9f29988f3258281956680ff39c3e19e37dc0b8.camel@perches.com
Signed-off-by: Joe Perches <joe@perches.com>
Reported-by: Sean Christopherson <sean.j.christopherson@intel.com>
Reviewed-by: Sean Christopherson <sean.j.christopherson@intel.com>
Tested-by: Sean Christopherson <sean.j.christopherson@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

scripts/checkpatch.pl

@@ -62,6 +62,8 @@ my $conststructsfile = "$D/const_structs.checkpatch";
 my $typedefsfile = "";
 my $color = "auto";
 my $allow_c99_comments = 1; # Can be overridden by --ignore C99_COMMENT_TOLERANCE
+# git output parsing needs US English output, so first set backtick child process LANGUAGE
+my $git_command ='export LANGUAGE=en_US.UTF-8; git';
 
 sub help {
 	my ($exitcode) = @_;
@@ -904,7 +906,7 @@ sub seed_camelcase_includes {
 	$camelcase_seeded = 1;
 
 	if (-e ".git") {
-		my $git_last_include_commit = `git log --no-merges --pretty=format:"%h%n" -1 -- include`;
+		my $git_last_include_commit = `${git_command} log --no-merges --pretty=format:"%h%n" -1 -- include`;
 		chomp $git_last_include_commit;
 		$camelcase_cache = ".checkpatch-camelcase.git.$git_last_include_commit";
 	} else {
@@ -932,7 +934,7 @@ sub seed_camelcase_includes {
 	}
 
 	if (-e ".git") {
-		$files = `git ls-files "include/*.h"`;
+		$files = `${git_command} ls-files "include/*.h"`;
 		@include_files = split('\n', $files);
 	}
 
@@ -956,7 +958,7 @@ sub git_commit_info {
 
 	return ($id, $desc) if ((which("git") eq "") || !(-e ".git"));
 
-	my $output = `git log --no-color --format='%H %s' -1 $commit 2>&1`;
+	my $output = `${git_command} log --no-color --format='%H %s' -1 $commit 2>&1`;
 	$output =~ s/^\s*//gm;
 	my @lines = split("\n", $output);
 
@@ -1006,7 +1008,7 @@ if ($git) {
 		} else {
 			$git_range = "-1 $commit_expr";
 		}
-		my $lines = `git log --no-color --no-merges --pretty=format:'%H %s' $git_range`;
+		my $lines = `${git_command} log --no-color --no-merges --pretty=format:'%H %s' $git_range`;
 		foreach my $line (split(/\n/, $lines)) {
 			$line =~ /^([0-9a-fA-F]{40,40}) (.*)$/;
 			next if (!defined($1) || !defined($2));