all: join a few chained ifs

I had been finding these over a year or so, but none were big enough
changes to warrant CLs. They're a handful now, so clean them all up in a
single commit.

The smaller bodies get a bit simpler, but most importantly, the larger
bodies get unindented.

Change-Id: I5707a6fee27d4c9ff9efd3d363af575d7a4bf2aa
Reviewed-on: https://go-review.googlesource.com/c/go/+/165340
Run-TryBot: Daniel Martí <mvdan@mvdan.cc>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>

encode.go

@@ -392,19 +392,15 @@ func newTypeEncoder(t reflect.Type, allowAddr bool) encoderFunc {
 	if t.Implements(marshalerType) {
 		return marshalerEncoder
 	}
-	if t.Kind() != reflect.Ptr && allowAddr {
-		if reflect.PtrTo(t).Implements(marshalerType) {
-			return newCondAddrEncoder(addrMarshalerEncoder, newTypeEncoder(t, false))
-		}
+	if t.Kind() != reflect.Ptr && allowAddr && reflect.PtrTo(t).Implements(marshalerType) {
+		return newCondAddrEncoder(addrMarshalerEncoder, newTypeEncoder(t, false))
 	}
 
 	if t.Implements(textMarshalerType) {
 		return textMarshalerEncoder
 	}
-	if t.Kind() != reflect.Ptr && allowAddr {
-		if reflect.PtrTo(t).Implements(textMarshalerType) {
-			return newCondAddrEncoder(addrTextMarshalerEncoder, newTypeEncoder(t, false))
-		}
+	if t.Kind() != reflect.Ptr && allowAddr && reflect.PtrTo(t).Implements(textMarshalerType) {
+		return newCondAddrEncoder(addrTextMarshalerEncoder, newTypeEncoder(t, false))
 	}
 
 	switch t.Kind() {