Remove the PatchOptions.Reverse option

All callers pass false now (except for the tests, which we simply remove), so we
don't need the option any more.

pkg/commands/patch/patch_manager.go

@@ -178,7 +178,6 @@ func (p *PatchManager) renderPlainPatchForFile(filename string, willBeAppliedRev
 		// generate a new diff with just the selected lines
 		return ModifiedPatchForLines(p.Log, filename, info.diff, info.includedLineIndices,
 			PatchOptions{
-				Reverse:              false,
 				WillBeAppliedReverse: willBeAppliedReverse,
 				KeepOriginalHeader:   true,
 			})