runtime/type: change fieldalign to use mixedCaps

All spelling in source code is "fieldAlign", except this place, so change
"fieldalign" to use mixedCaps.

Change-Id: Icbd9b9d23d9b4f756174e9a3cc4b25776fd90def
GitHub-Last-Rev: 44a4fe1
GitHub-Pull-Request: #34441
Reviewed-on: https://go-review.googlesource.com/c/go/+/196757
Run-TryBot: Andrew Bonventre <andybons@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Daniel Martí <mvdan@mvdan.cc>

src/runtime/type.go

@@ -32,7 +32,7 @@ type _type struct {
 	hash       uint32
 	tflag      tflag
 	align      uint8
-	fieldalign uint8
+	fieldAlign uint8
 	kind       uint8
 	// function for comparing objects of this type
 	// (ptr to object A, ptr to object B) -> ==?