niter: Fix up unused var warning [PR108457]

niter: Fix up unused var warning [PR108457]

tree-ssa-loop-niter.cc (build_cltz_expr) gets unused variable mode
warning on some architectures where C[LT]Z_DEFINED_VALUE_AT_ZERO
macro(s) don't use the first argument (which includes the
defaults.h definitions of:
 #define CLZ_DEFINED_VALUE_AT_ZERO(MODE, VALUE)  0
 #define CTZ_DEFINED_VALUE_AT_ZERO(MODE, VALUE)  0
Other uses of this macro avoid this problem by avoiding temporaries
which are only used as argument to those macros, the following patch
does it the same way for consistency.  Plus some formatting fixes
while at it.

2023-01-20  Jakub Jelinek  <jakub@redhat.com>

	PR tree-optimization/108457
	* tree-ssa-loop-niter.cc (build_cltz_expr): Use
	SCALAR_INT_TYPE_MODE (utype) directly as C[LT]Z_DEFINED_VALUE_AT_ZERO
	argument instead of a temporary.  Formatting fixes.