x86, microcode: Simplify vfree() use

vfree() does its own 'NULL' check, so no need for check before
calling it.

In v2, remove the stray newline.

[ Impact: cleanup ]

Signed-off-by: Figo.zhang <figo1802@gmail.com>
Cc: Dmitry Adamushko <dmitry.adamushko@gmail.com>
LKML-Reference: <1244385036.3402.11.camel@myhost>
Signed-off-by: Ingo Molnar <mingo@elte.hu>