x86/microcode/amd: Use correct per CPU ucode_cpu_info

find_blobs_in_containers() is invoked on every CPU but overwrites
unconditionally ucode_cpu_info of CPU0.

Fix this by using the proper CPU data and move the assignment into the
call site apply_ucode_from_containers() so that the function can be
reused.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Link: https://lore.kernel.org/r/20231010150702.433454320@linutronix.de