Variable err is not uninitialized and hence can potentially contain
any garbage value.  This may cause an error when logical or'ing the
return values from the calls to functions crypto_aead_setauthsize or
crypto_aead_setkey.  Fix this by setting err to the return of
crypto_aead_setauthsize rather than or'ing in the return into the
uninitialized variable

Addresses-Coverity: ("Uninitialized scalar variable")
Fixes: fc1b6d6d ("tipc: introduce TIPC encryption & authentication")
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Signed-off-by: David S. Miller <davem@davemloft.net>