ALSA: rawmidi: fix incorrect array bounds check on clock_names

ALSA: rawmidi: fix incorrect array bounds check on clock_names

The array bounds check on clock_names is currently checking the size
of the entire array rather than the number of elements in the array
leading to a potential array bounds read error. Fix this by using
the ARRAY_SIZE macro instead of sizeof.

Addresses-Coverity: ("Out-of-bounds read")
Fixes: 08fdced60ca0 ("ALSA: rawmidi: Add framing mode")
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Link: https://lore.kernel.org/r/20210519105424.55221-1-colin.king@canonical.com
Signed-off-by: Takashi Iwai <tiwai@suse.de>