Do not validate the volume source path in specgen

The volume src path should not be validated in specgen since
the remote client also uses that part and the path must only
exists on the server. This now fails later and only on the
server and not the client.

I don't think I can add a test for this because the CI runs
server and client always on the same vm.

Fixes #8473

Signed-off-by: Paul Holzinger <paul.holzinger@web.de>

cmd/podman/common/volumes.go

@@ -323,8 +323,8 @@ func getBindMount(args []string) (spec.Mount, error) {
 			if len(kv) == 1 {
 				return newMount, errors.Wrapf(optionArgError, kv[0])
 			}
-			if err := parse.ValidateVolumeHostDir(kv[1]); err != nil {
+			if len(kv[1]) == 0 {
-				return newMount, err
+				return newMount, errors.Wrapf(optionArgError, "host directory cannot be empty")
 			}
 			newMount.Source = kv[1]
 			setSource = true

pkg/specgen/volumes.go

@@ -84,11 +84,10 @@ func GenVolumeMounts(volumeFlag []string) (map[string]spec.Mount, map[string]*Na
 				return nil, nil, nil, err
 			}
 		}
-
 		// Do not check source dir for anonymous volumes
 		if len(splitVol) > 1 {
-			if err := parse.ValidateVolumeHostDir(src); err != nil {
+			if len(src) == 0 {
-				return nil, nil, nil, err
+				return nil, nil, nil, errors.New("host directory cannot be empty")
 			}
 		}
 		if err := parse.ValidateVolumeCtrDir(dest); err != nil {