net/mlx5: fix log initialization

net/mlx5: fix log initialization

The mlx5 driver had two init functions, but this could
cause log initialization to be done after the
other initialization. Also, the name of the function does
not match convention (cut/paste error?).

Fix by initializing log type first at start of the pmd_init.
This also gets rid of having two constructor functions.

Fixes: a170a30d22a8 ("net/mlx5: use dynamic logging")
Cc: stable@dpdk.org
Signed-off-by: Stephen Hemminger <stephen@networkplumber.org>
Acked-by: Nelio Laranjeiro <nelio.laranjeiro@6wind.com>