util/lint/checkpatch.pl: Fix "Invalid color mode" error message

Remove duplicated code:
"if ($color =~ /^[01]$/) {
	$color = !$color;
} elsif ($color =~ /^always$/i) {
	$color = 1;
} elsif ($color =~ /^never$/i) {
	$color = 0;
} elsif ($color =~ /^auto$/i) {
	$color = (-t STDOUT);
} else {
	die "$P: Invalid color mode: $color\n";
}"

Change-Id: I5713c364edea806e58df26c3a37b4bba7603ed0a
Signed-off-by: Elyes Haouas <ehaouas@noos.fr>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/64172
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Martin L Roth <gaumless@tutanota.com>
diff --git a/util/lint/checkpatch.pl b/util/lint/checkpatch.pl
index 81fda35..a7a31db 100755
--- a/util/lint/checkpatch.pl
+++ b/util/lint/checkpatch.pl
@@ -398,18 +398,6 @@
 # skip TAB size 1 to avoid additional checks on $tabsize - 1
 die "$P: Invalid TAB size: $tabsize\n" if ($tabsize < 2);
 
-if ($color =~ /^[01]$/) {
-	$color = !$color;
-} elsif ($color =~ /^always$/i) {
-	$color = 1;
-} elsif ($color =~ /^never$/i) {
-	$color = 0;
-} elsif ($color =~ /^auto$/i) {
-	$color = (-t STDOUT);
-} else {
-	die "Invalid color mode: $color\n";
-}
-
 sub hash_save_array_words {
 	my ($hashRef, $arrayRef) = @_;