fix trailing whitespaces (#917)

testdata/confusing-results.go

@@ -4,7 +4,7 @@ func getfoo() (int, int, error) { // MATCH /unnamed results of the same type may
 
 }
 
-func getBar(a, b int) (int, error, int) { 
+func getBar(a, b int) (int, error, int) {
 }
 
 func Getbaz(a string, b int) (int, float32, string, string) { // MATCH /unnamed results of the same type may be confusing, consider using named results/

testdata/duplicated-imports.go

@@ -1,7 +1,7 @@
 package fixtures
 
 import(
-	"crypto/md5"  
+	"crypto/md5"
         "strings"
         _ "crypto/md5" // MATCH /Package "crypto/md5" already imported/
         str "strings"  // MATCH /Package "strings" already imported/

testdata/golint/error-strings.go

@@ -16,7 +16,7 @@ func g(x int) error {
 	err = fmt.Errorf("Newlines are really fun\n") // MATCH /error strings should not be capitalized or end with punctuation or a newline/
 	err = errors.New(`too much stuff.`)           // MATCH /error strings should not be capitalized or end with punctuation or a newline/
 	err = errors.New("This %d is too low", x)     // MATCH /error strings should not be capitalized or end with punctuation or a newline/
-		
+
 	// Non-regression test for issue #610
 	d.stack.Push(from)