IB/iser: Fix sparse warnings

commit 49df2781b101a729e9f46eddc845a587fc5665a8 upstream.

Use uintptr_t to handle wr_id casting, which was found by Kbuild test
robot and smatch.  Also remove an internal definition of variable which
potentially shadows an external one (and make sparse happy).

Signed-off-by: Sagi Grimberg <sagig@mellanox.com>
Signed-off-by: Or Gerlitz <ogerlitz@mellanox.com>
Signed-off-by: Roland Dreier <roland@purestorage.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>