CVE-2022-49177 hwrng: cavium - fix NULL but dereferenced coccicheck error

In the Linux kernel, the following vulnerability has been resolved: hwrng: cavium - fix NULL but dereferenced coccicheck error Fix following coccicheck warning: ./drivers/char/hwrandom/cavium-rng-vf.c:182:17-20: ERROR: pdev is NULL but dereferenced...