Revert "XFAIL entry_point_func.ll after a45b133 (#3117)"

This reverts commit 59fd9db.

Author: jsji

llvm-spirv/test/entry_point_func.ll

@@ -5,9 +5,6 @@
 ; RUN: llvm-spirv %t.bc -o %t.spv
 ; RUN: spirv-val %t.spv
 
-; TODO: adjust the test or revert XFAIL
-; XFAIL: *
-
 target datalayout = "e-i64:64-v16:16-v24:32-v32:32-v48:64-v96:128-v192:256-v256:256-v512:512-v1024:1024-n8:16:32:64"
 target triple = "spir64-unknown-unknown"