RDMA/cxgb4: Delete an unnecessary check before kfree() in c4iw_rdev_open()

RDMA/cxgb4: Delete an unnecessary check before kfree() in c4iw_rdev_open()

It can be known that the function “kfree” performs a null pointer check
for its input parameter.
It is therefore not needed to repeat such a check before its call.

Thus remove a redundant pointer check.

The source code was transformed by using the Coccinelle software.

Signed-off-by: Markus Elfring <elfring@users.sourceforge.net>
Link: https://patch.msgid.link/cdc577a5-cebd-404a-b762-cc6fee0870dc@web.de
Signed-off-by: Leon Romanovsky <leon@kernel.org>