On my device the rpmsg0 have DATA5_CNTL under name attribute instead of
rpmsg_name
```
looking at device '/devices/platform/smd/smd:modem/smd:modem.rpmsg_chrdev.0.0/rpmsg/rpmsg_ctrl1/rpmsg0':
KERNEL=="rpmsg0"
SUBSYSTEM=="rpmsg"
DRIVER==""
ATTR{dst}=="0"
ATTR{src}=="0"
ATTR{name}=="DATA5_CNTL"
```
So check for name instead of rpmsg_name.