[WebAssembly] Fix typo in relocation checking

Runtime relocation are generated for relocations of type
R_WASM_MEMORY_ADDR_I32 when in PIC mode (either -shared or -pie).

Followup on https://reviews.llvm.org/D60882.

Differential Revision: https://reviews.llvm.org/D60992

llvm-svn: 358995