gitweb: Cleanup - chomp @lines in consistent style

gitweb: Cleanup - chomp @lines in consistent style

Use 'my @lines = map { chomp; $_ } <$fd>;' form to read all lines of
git command output into array without trailing newlines.

It has advantage over 'chomp (my (@lines) = <$fd>);' in that it does
not modify array.

Signed-off-by: Jakub Narebski <redacted>
Signed-off-by: Junio C Hamano <redacted>