BaseTools/PatchCheck.py: Ignore CR and LF characters in subject length

BaseTools/PatchCheck.py: Ignore CR and LF characters in subject length

REF: https://bugzilla.tianocore.org/show_bug.cgi?id=113

Strip the trailing characters before checking the subject line is
less than 72 characters.

Fixes: e61406708c83f
Cc: Liming Gao <liming.gao@intel.com>
Cc: Jordan Justen <jordan.l.justen@intel.com>
Reviewed-by: Jordan Justen <jordan.l.justen@intel.com>
Reviewed-by: Bob Feng <bob.c.feng@intel.com>
Signed-off-by: Philippe Mathieu-Daude <philmd@redhat.com>