alsa-lib: fix the array parser (unique compound keys)

alsa-lib: fix the array parser (unique compound keys)

The code from the old import may merge arrays wrongly and
the result is a compound with same keys like:

Input:

        lines [
                "SSP0.OUT, , BUF1.3"
        ]
        lines [
                "BUF2.0, , SSP0.IN"
        ]

Parsed contents:

        lines {
                0 'SSP0.OUT, , BUF1.3'
                0 'BUF2.0, , SSP0.IN'
        }

Proper parsed contents (create+merge mode):

        lines {
                0 'SSP0.OUT, , BUF1.3'
                1 'BUF2.0, , SSP0.IN'
        }

Signed-off-by: Jaroslav Kysela <perex@perex.cz>