nfp: bpf: Add check for nfp_app_ctrl_msg_alloc()

nfp: bpf: Add check for nfp_app_ctrl_msg_alloc()

commit 878e7b11736e062514e58f3b445ff343e6705537 upstream.

Add check for the return value of nfp_app_ctrl_msg_alloc() in
nfp_bpf_cmsg_alloc() to prevent null pointer dereference.

Fixes: ff3d43f7568c ("nfp: bpf: implement helpers for FW map ops")
Cc: stable@vger.kernel.org
Signed-off-by: Haoxiang Li <haoxiang_li2024@163.com>
Link: https://patch.msgid.link/20250218030409.2425798-1-haoxiang_li2024@163.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>