Fix missing change of Ctrl key in README

PR #1652 <https://github.com/Genymobile/scrcpy/pull/1652>
Signed-off-by: NRomain Vimont <rom@rom1v.com>

README.md

@@ -449,7 +449,7 @@ Or by pressing <kbd>MOD</kbd>+<kbd>o</kbd> at any time.
 To turn it back on, press <kbd>MOD</kbd>+<kbd>Shift</kbd>+<kbd>o</kbd>.
 
 On Android, the `POWER` button always turns the screen on. For convenience, if
-`POWER` is sent via scrcpy (via right-click or <kbd>Ctrl</kbd>+<kbd>p</kbd>), it
+`POWER` is sent via scrcpy (via right-click or <kbd>MOD</kbd>+<kbd>p</kbd>), it
 will force to turn the screen off after a small delay (on a best effort basis).
 The physical `POWER` button will still cause the screen to be turned on.