net/mlx4: Check retval of mlx4_bitmap_init

net/mlx4: Check retval of mlx4_bitmap_init

If mlx4_bitmap_init fails, mlx4_bitmap_alloc_range will dereference
the NULL pointer (bitmap->table).

Make sure, that mlx4_bitmap_alloc_range called in no error case.

Found by Linux Verification Center (linuxtesting.org) with SVACE.

Fixes: 08e1283e04dc ("net/mlx4: Add A0 hybrid steering")
Reviewed-by: Tariq Toukan <tariqt@nvidia.com>
Signed-off-by: Peter Kosyh <pkosyh@yandex.ru>
Link: https://lore.kernel.org/r/20221117152806.278072-1-pkosyh@yandex.ru
Signed-off-by: Jakub Kicinski <kuba@kernel.org>