x86/microcode: Remove unnecessary perf callback

c93dc84c ("perf/x86: Add a microcode revision check for SNB-PEBS")
checks whether the microcode revision has fixed PEBS issues.

This can happen either:

1. At PEBS init time, where the early microcode has been loaded already

2. During late loading, in the microcode_check() callback.

So remove the unnecessary call in the microcode loader init routine.

Signed-off-by: Borislav Petkov <bp@suse.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/20220525161232.14924-5-bp@alien8.de