[GISel]: Remove an incorrect assert in CallLowering

https://reviews.llvm.org/D51147

Asserting if any extend of vectors should be up to the target's
legalizer/target specific code not in CallLowering.

reviewed by : dsanders.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@343325 91177308-0d34-0410-b5e6-96231b3b80d8
2 files changed