CVE-2022-50765 RISC-V: kexec: Fix memory leak of elf header buffer

In the Linux kernel, the following vulnerability has been resolved: RISC-V: kexec: Fix memory leak of elf header buffer This is reported by kmemleak detector: unreferenced object 0xff2000000403d000 size 4096: comm "kexec", pid 146, jiffies 4294900633 age 64.792s hex dump first 32 bytes: 7f 45 4c ...