x86/microcode/intel: Simplify scan_microcode()

mainline inclusion
from mainline-v6.7-rc1
commit b0f0bf5eef5fac6ba30b7cac15ca4cb01f8a6ca9
category: feature
bugzilla: https://gitee.com/openeuler/intel-kernel/issues/I8XRMW


CVE: NA

--------------------------------

Make it readable and comprehensible.

Intel-SIG: commit b0f0bf5eef5f x86/microcode/intel: Simplify scan_microcode().
Microcode restructuring backport.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Link: https://lore.kernel.org/r/20231002115902.271940980@linutronix.de


[ Aubrey Li: amend commit log ]
Signed-off-by: Aubrey Li <aubrey.li@linux.intel.com>