rustc_codegen_llvm: Remove reference to non-existing no_landing_pads()

Removing this reference was forgotten in eb4725fc54. Grepping for
no_landing_pads returns no hits after this.

compiler/rustc_codegen_llvm/src/attributes.rs

@@ -377,12 +377,11 @@ pub(crate) fn llfn_attrs_from_instance<'ll, 'tcx>(
     //     that no exceptions passes by it. This is normally the case for the
     //     ELF x86-64 abi, but it can be disabled for some compilation units.
     //
-    // Typically when we're compiling with `-C panic=abort` (which implies this
-    // `no_landing_pads` check) we don't need `uwtable` because we can't
-    // generate any exceptions! On Windows, however, exceptions include other
-    // events such as illegal instructions, segfaults, etc. This means that on
-    // Windows we end up still needing the `uwtable` attribute even if the `-C
-    // panic=abort` flag is passed.
+    // Typically when we're compiling with `-C panic=abort` we don't need
+    // `uwtable` because we can't generate any exceptions! On Windows, however,
+    // exceptions include other events such as illegal instructions, segfaults,
+    // etc. This means that on Windows we end up still needing the `uwtable`
+    // attribute even if the `-C panic=abort` flag is passed.
     //
     // You can also find more info on why Windows always requires uwtables here:
     //      https://bugzilla.mozilla.org/show_bug.cgi?id=1302078