checkpatch: Don't check for mutex_trylock_recursive()

mutex_trylock_recursive() has been removed from the tree, there is no
need to check for it.

Remove traces of mutex_trylock_recursive()'s existence.

Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20210210085248.219210-3-bigeasy@linutronix.de