cleanup: address golangci 'usetesting' linter issues

When a context.Context is needed in a unit test, t.Context() should be
used instead of creating a new one with context.TODO() or
context.Background().

Signed-off-by: Niels de Vos <ndevos@ibm.com>

internal/util/cephcmds_test.go

@@ -41,7 +41,7 @@ func TestExecCommandWithTimeout(t *testing.T) {
 		{
 			name: "echo hello",
 			args: args{
-				ctx:     context.TODO(),
+				ctx:     t.Context(),
 				program: "echo",
 				timeout: time.Second,
 				args:    []string{"hello"},
@@ -53,7 +53,7 @@ func TestExecCommandWithTimeout(t *testing.T) {
 		{
 			name: "sleep with timeout",
 			args: args{
-				ctx:     context.TODO(),
+				ctx:     t.Context(),
 				program: "sleep",
 				timeout: time.Second,
 				args:    []string{"3"},