remove unintentional debug prints

These were introduced when syncing gofumpt with gofmt from Go 1.18rc1.
I didn't notice partially because our tests weren't strict enough;
fix that as well.

While here, gofumpt our own source code.

format/format.go

@@ -912,7 +912,6 @@ func (f *fumpter) joinStdImports(d *ast.GenDecl) {
 		periodIndex := strings.IndexByte(path, '.')
 		slashIndex := strings.IndexByte(path, '/')
 		switch {
-
 		// Imports with a period in the first path element are third party.
 		// Note that this includes "foo.com" and excludes "foo/bar.com/baz".
 		case periodIndex > 0 && (slashIndex == -1 || periodIndex < slashIndex),

gofmt.go

@@ -502,9 +502,7 @@ func gofmtMain(s *sequencer) {
 		case !info.IsDir():
 			// Non-directory arguments are always formatted.
 			arg := arg
-			println(arg)
 			s.Add(fileWeight(arg, info), func(r *reporter) error {
-				println(arg)
 				return processFile(arg, info, nil, r, true)
 			})
 		default:

testdata/scripts/ignore-implicit-vendor.txt

@@ -5,21 +5,25 @@ cp orig.go.golden vendor/foo/foo.go
 
 # format explicit vendor dir
 gofumpt -l vendor
-stdout 'vendor[/\\]foo[/\\]foo.go'
+stdout -count=1 'vendor[/\\]foo[/\\]foo.go'
+! stderr .
 
 # format explicit vendor file
 gofumpt -l vendor/foo/foo.go
-stdout 'vendor[/\\]foo[/\\]foo.go'
+stdout -count=1 'vendor[/\\]foo[/\\]foo.go'
+! stderr .
 
 # ignore implicit vendor call
 gofumpt -l .
 ! stdout .
+! stderr .
 
 # format explicit vendor pkg while ignoring rest
 mkdir vendor/ignore
 cp orig.go.golden vendor/ignore/ignore.go
 gofumpt -l vendor/foo .
-stdout 'vendor[/\\]foo[/\\]foo.go'
+stdout -count=1 'vendor[/\\]foo[/\\]foo.go'
+! stderr .
 
 -- orig.go.golden --
 package p