Adjust gcc.target/i386/pr89523-1{a,b}.c

The following removes the scan for a addr32 vgather, but keeps the
negative scan for vgather.  There is no reason for using a gather
in the first place and after hoisting the invariant load of the
ncost pointer load from the unswitched loop body we don't use one.

	PR testsuite/127048
	* gcc.target/i386/pr89523-1a.c: Remove scan for addr32 vgather.
	* gcc.target/i386/pr89523-1b.c: Likewise.