preproc.c: remove "!= NULL" from asserts

For consistency with the rest of the codebase.

This amends commit 53bc658 ("modif: improve flock handling",
2024-04-17) / #6307.

Author: kmk3

src/firejail/preproc.c

@@ -28,8 +28,8 @@
 static int tmpfs_mounted = 0;
 
 static void preproc_lock_file(const char *path, int *lockfd_ptr) {
-	assert(path != NULL);
-	assert(lockfd_ptr != NULL);
+	assert(path);
+	assert(lockfd_ptr);
 
 	long pid = (long)getpid();
 	if (arg_debug)
@@ -63,8 +63,8 @@ static void preproc_lock_file(const char *path, int *lockfd_ptr) {
 }
 
 static void preproc_unlock_file(const char *path, int *lockfd_ptr) {
-	assert(path != NULL);
-	assert(lockfd_ptr != NULL);
+	assert(path);
+	assert(lockfd_ptr);
 
 	long pid = (long)getpid();
 	if (arg_debug)