libsel4allocman: Fix missing initialised field.

This commit fixes an instance where a struct was initialised with an incorrect
number of fields. The compiler figured out what was meant, so no harm was done,
but the previous code was technically incorrect.

libsel4allocman/src/cspace/two_level.c

diff --git a/libsel4allocman/src/cspace/two_level.c b/libsel4allocman/src/cspace/two_level.c
index 0cb6d65..4667680 100644
--- a/libsel4allocman/src/cspace/two_level.c
+++ b/libsel4allocman/src/cspace/two_level.c
@@ -28,7 +28,7 @@
        could be a two level cspace and this would still work */
     if(!cspace->second_levels[l1slot]) {
         assert(!"ERROR: Tried make a path to a non existant slot\n");
-        return (cspacepath_t) {0, 0, 0, 0, 0, 0};
+        return (cspacepath_t) {0, 0, 0, 0, 0, 0, 0};
     }
     l1_path = _cspace_single_level_make_path(&cspace->first_level, l1slot);
     l2_path =_cspace_single_level_make_path(&cspace->second_levels[l1slot]->second_level, l2slot);