flock07: Initialize the sigaction structure

The sigaction structure for child SIGUSR1 handler was uninitialized,
which sometimes resulted in SA_RESTART flag being enabled by accident
and the child flock() call never returning. Make sure the sigaction
structure is properly initialized.

Signed-off-by: Martin Doucha <mdoucha@suse.cz>
Reviewed-by: Avinesh Kumar <akumar@suse.de>
Reviewed-by: Andrea Cervesato <andrea.cervesato@suse.com>

Author: mdoucha

testcases/kernel/syscalls/flock/flock07.c

@@ -42,7 +42,7 @@ static void cleanup(void)
 
 static void child_do(int fd)
 {
-	struct sigaction sa;
+	struct sigaction sa = {};
 
 	sa.sa_handler = handler;
 	SAFE_SIGEMPTYSET(&sa.sa_mask);