Staging: speakup: Use sizeof(*var) in kmalloc().

Modifying struct allocation in kmalloc() to match the
coding standards.

Checkpatch.pl CHECK: Prefer kmalloc(sizeof(*ldisc_data)...)
over kmalloc(sizeof(struct spk_ldisc_data)...)

Signed-off-by: Sam Muhammed <[e-mail]>
Reviewed-by: Samuel Thibault <[e-mail]>
Link: https://lore.kernel.org/r/1[e-mail]
Signed-off-by: Greg Kroah-Hartman <[e-mail]>

drivers/staging/speakup/spk_ttyio.c

···
 		return -EOPNOTSUPP;
 	speakup_tty = tty;
 
-	ldisc_data = kmalloc(sizeof(struct spk_ldisc_data), GFP_KERNEL);
+	ldisc_data = kmalloc(sizeof(*ldisc_data), GFP_KERNEL);
 	if (!ldisc_data)
 		return -ENOMEM;