README: remove backtick typo (commaai#1040)

Author: ErichMoraga

drivers/linux/README.md

@@ -25,5 +25,5 @@ sudo tee /etc/udev/rules.d/11-panda.rules <<EOF
 SUBSYSTEM=="usb", ATTRS{idVendor}=="bbaa", ATTRS{idProduct}=="ddcc", MODE="0666"
 SUBSYSTEM=="usb", ATTRS{idVendor}=="bbaa", ATTRS{idProduct}=="ddee", MODE="0666"
 EOF
-sudo udevadm control --reload-rules && sudo udevadm trigger`
+sudo udevadm control --reload-rules && sudo udevadm trigger
 ```