abilint: Add prompt message for abnormal operation

abilint: Add prompt message for abnormal operation

When using abilint, if the user provides the --stdin option as well as
a file path on the command line, the file path is silently ignored.

This patch provides a warning to notify the user that the file path is
ignored in that case.

	* tools/abilint.cc (parse_command_line): Notify the user when the
	path to the file is ignored because the --stdin option was
	provided.

Signed-off-by: tangmeng <tangmeng@uniontech.com>
Signed-off-by: Dodji Seketeli <dodji@redhat.com>