fou: fix initialization of grc

The grc must be initialize first. There can be a condition where if
fou is NULL, goto out will be executed and grc would be used
uninitialized.

Fixes: 7e419693 ("fou: Fix null-ptr-deref in GRO.")
Signed-off-by: Muhammad Usama Anjum <usama.anjum@collabora.com>
Reviewed-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Link: https://patch.msgid.link/20240906102839.202798-1-usama.anjum@collabora.com


Signed-off-by: Jakub Kicinski <kuba@kernel.org>