Ensure we don't end up with a null pointer dereferences by checking
for for allocation failures.  Allocate by sizeof(*ptr) rather than
the type to fix checkpack warnings.  Also merge multiple lines into
one line for the kmalloc call.

Detected by CoverityScan, CID#1422435 ("Dereference null return value")
Signed-off-by: NColin Ian King <colin.king@canonical.com>
Signed-off-by: NMarcel Holtmann <marcel@holtmann.org>