IconCache: remove incorrect ASSERT()

The code does just fine both if entry is NULL and if it doesn't have an
icon. However, if entry is NULL, this assert calls a method on it, which
is a bad idea.

Change-Id: I80b314db373970d99eb008aeaec6254d14c39ca7
Reviewed-on: https://review.haiku-os.org/c/haiku/+/1749
Reviewed-by: Stephan Aßmus <[email protected]>

src/kits/tracker/IconCache.cpp

@@ -1007,7 +1007,6 @@ IconCache::Preload(AutoLock<SimpleIconCache>* nodeCacheLocker,
 
 					entry = GetIconFromFileTypes(&modelOpener, source, mode,
 						size, &lazyBitmap, 0);
-					ASSERT(entry != NULL || entry->HaveIconBitmap(mode, size));
 
 					if (entry == NULL || !entry->HaveIconBitmap(mode, size)) {
 						// we don't have an icon, go with the generic