bpf: Remove redundant initialization of variable allow

The variable allow is being initialized with a value that is never read, it
is being updated later on. The assignment is redundant and can be removed.

Addresses-Coverity: ("Unused value")

Signed-off-by: Colin Ian King <colin.king@canonical.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20210817170842.495440-1-colin.king@canonical.com