s390/ctcm: Fix double-kfree

s390/ctcm: Fix double-kfree

The function 'mpc_rcvd_sweep_req(mpcginfo)' is called conditionally
from function 'ctcmpc_unpack_skb'. It frees passed mpcginfo.
After that a call to function 'kfree' in function 'ctcmpc_unpack_skb'
frees it again.

Remove 'kfree' call in function 'mpc_rcvd_sweep_req(mpcginfo)'.

Bug detected by the clang static analyzer.

Fixes: 0c0b20587b9f25a2 ("s390/ctcm: fix potential memory leak")
Reviewed-by: Aswin Karuvally <aswin@linux.ibm.com>
Signed-off-by: Aleksei Nikiforov <aleksei.nikiforov@linux.ibm.com>
Signed-off-by: Aswin Karuvally <aswin@linux.ibm.com>
Reviewed-by: Simon Horman <horms@kernel.org>
Link: https://patch.msgid.link/20251112182724.1109474-1-aswin@linux.ibm.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>