refactor(userspace/falco): remove duplicate condition test

handled is test a second time for the same while it's already
part of the initial entry condition.

Signed-off-by: Samuel Gaist <samuel.gaist@idiap.ch>

userspace/falco/atomic_signal_handler.h

@@ -85,7 +85,6 @@ public:
 	inline bool handle(std::function<void()> f) {
 		if(triggered() && !handled()) {
 			std::unique_lock<std::mutex> lock(m_mtx);
-			if(!handled()) {
 			try {
 				f();
 				// note: the action may have forcely reset
@@ -102,7 +101,6 @@ public:
 			}
 			return true;
 		}
-		}
 		return false;
 	}