mount.nfs: print more useful error message

When mounting spec of a regular file, mount.nfs print error message as,

# mount -t nfs 127.0.0.1:/root/testfile /mnt/
mount.nfs: mount point /mnt is not a directory
# mount -t nfs 127.0.0.1:/root/testfile /mnt/testfile
mount.nfs: mount point /mnt/testfile is not a directory

This patch lets mount.nfs print more useful message,

# mount -t nfs 127.0.0.1:/root/testfile /mnt/
mount.nfs: mount spec 127.0.0.1:/root/testfile or point /mnt is not a directory
# mount -t nfs 127.0.0.1:/root/testfile /mnt/testfile
mount.nfs: mount point /mnt/testfile is not a directory

Signed-off-by Kinglong Mee <[email protected]>

---
 utils/mount/error.c | 8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)

utils/mount/error.c +6 -2

index f8fc13f..e06f598 100644
@@ -215,8 +215,12 @@ void mount_error(const char *spec, const char *mount_point, int error)
 				progname);
 		break;
 	case ENOTDIR:
-		nfs_error(_("%s: mount point %s is not a directory"),
-				progname, mount_point);
+		if (spec)
+			nfs_error(_("%s: mount spec %s or point %s is not a "
+				  "directory"),	progname, spec, mount_point);
+		else
+			nfs_error(_("%s: mount point %s is not a directory"),
+				  progname, mount_point);
 		break;
 	case EBUSY:
 		nfs_error(_("%s: %s is busy or already mounted"),