[llvm] [X86] Fixed type bug in vselect for AVX masked load

Summary:
Bugzilla issue 45563
https://bugs.llvm.org/show_bug.cgi?id=45563

Reviewers: nicolasvasilache, mehdi_amini, craig.topper

Reviewed By: craig.topper

Subscribers: RKSimon, hiraditya, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D78527