get_maintainer.pl: teach git log to use --no-color

When git has been set to always use color in .gitconfig then I get the
warning message

        Bad divisor in main::vcs_assign: 0

This is caused by vcs_file_signoffs not matching any commits due to the
pattern not understand the colour codes.  Fix this by telling git log to
never use colour.

Signed-off-by: Richard Kennedy <richard@rsk.demon.co.uk>
Acked-by: Joe Perches <joe@perches.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

scripts/get_maintainer.pl

@@ -74,8 +74,8 @@ my %VCS_cmds;
 my %VCS_cmds_git = (
     "execute_cmd" => \&git_execute_cmd,
     "available" => '(which("git") ne "") && (-d ".git")',
-    "find_signers_cmd" => "git log --since=\$email_git_since -- \$file",
-    "find_commit_signers_cmd" => "git log -1 \$commit",
+    "find_signers_cmd" => "git log --no-color --since=\$email_git_since -- \$file",
+    "find_commit_signers_cmd" => "git log --no-color -1 \$commit",
     "blame_range_cmd" => "git blame -l -L \$diff_start,+\$diff_length \$file",
     "blame_file_cmd" => "git blame -l \$file",
     "commit_pattern" => "^commit [0-9a-f]{40,40}",