react/cmd/reactGen: crash when judge HasEquals

[lijianying10]

ON

x/react/cmd/reactGen/comp_gen.go

Line 129 in 470b165

if m.Type.Results != nil && len(m.Type.Results.List) != 1 {

When m.Type.Results is nil the

x/react/cmd/reactGen/comp_gen.go

Line 133 in 470b165

rp := m.Type.Results.List[0]

will panic with nil pointer dereference.

Same bug on line:

x/react/cmd/reactGen/comp_gen.go

Line 153 in 470b165

if m.Type.Params != nil && len(m.Type.Params.List) != 1 {

x/react/cmd/reactGen/comp_gen.go

Line 157 in 470b165

if m.Type.Results != nil && len(m.Type.Results.List) != 1 {