ipv6: sr: fix passing wrong flags to crypto_alloc_shash()

[ Upstream commit fc9c2029e37c3ae9efc28bf47045e0b87e09660c ]

The 'mask' argument to crypto_alloc_shash() uses the CRYPTO_ALG_* flags,
not 'gfp_t'.  So don't pass GFP_KERNEL to it.

Fixes: bf355b8d ("ipv6: sr: add core files for SR HMAC support")
Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>