display_error_msgs() is never called to show messages of both ERROR_*
and WARNING_* types at the same time; it is instead called multiple
times, separately for each type. Since we want to display these types
differently, make two slightly different versions of this function.
A subsequent commit will further modify unpack_trees() and how it calls
the new display_warning_msgs().
Reviewed-by: Derrick Stolee <dstolee@microsoft.com> Signed-off-by: Elijah Newren <newren@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>