mountinfo: GetMountsFromReader() remove redundant switch

This switch was implementing the exact same check as is done in
strings.Join(); https://cs.opensource.google/go/go/+/refs/tags/go1.16.7:src/strings/strings.go;l=421-427

This only difference removing this switch makes is that it will assign
an empty string to p.Optional if no optional fields are present, but
given that an empty string is the default value for p.Optional, this
should make no difference.

Signed-off-by: Sebastiaan van Stijn <github@gone.nl>

Author: thaJeztah

mountinfo/mountinfo_linux.go

@@ -105,16 +105,9 @@ func GetMountsFromReader(r io.Reader, filter FilterFunc) ([]*Info, error) {
 		p.Options = fields[5]
 
 		// zero or more optional fields
-		switch {
-		case sepIdx == 6:
-			// zero, do nothing
-		case sepIdx == 7:
-			p.Optional = fields[6]
-		default:
-			p.Optional = strings.Join(fields[6:sepIdx-1], " ")
-		}
+		p.Optional = strings.Join(fields[6:sepIdx-1], " ")
 
-		// Run the filter after parsing all of the fields.
+		// Run the filter after parsing all fields.
 		var skip, stop bool
 		if filter != nil {
 			skip, stop = filter(p)