Fix extra non_snake_case warning for shorthand field bindings

[FabianWolff]

Fixes #89469. The problem is the innermost if condition here:

rust/compiler/rustc_lint/src/nonstandard_style.rs

Lines 435 to 452 in d14731c

	fn check_pat(&mut self, cx: &LateContext<'_>, p: &hir::Pat<'_>) {
	if let PatKind::Binding(_, hid, ident, _) = p.kind {
	if let hir::Node::Pat(parent_pat) = cx.tcx.hir().get(cx.tcx.hir().get_parent_node(hid))
	{
	if let PatKind::Struct(_, field_pats, _) = &parent_pat.kind {
	for field in field_pats.iter() {
	if field.ident != ident {
	// Only check if a new name has been introduced, to avoid warning
	// on both the struct definition and this pattern.
	self.check_snake_case(cx, "variable", &ident);
	}
	}
	return;
	}
	}
	self.check_snake_case(cx, "variable", &ident);
	}
	}

This code runs for every PatKind::Binding, so if a struct has multiple fields, say A and B, and both are bound in a pattern using shorthands, the call to self.check_snake_case() will indeed be skipped in the check_pat() call for A; but when check_pat() is called for B, the loop will still iterate over A, and field.ident (= A) != ident (= B) will be true. I have fixed this by only looking at non-shorthand bindings, and only the binding that check_pat() was actually called for.

[rust-highfive]

r? @davidtwco

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[joshtriplett]

@bors r+

[bors]

📌 Commit 9626f2b has been approved by joshtriplett