kernel/file_cache: Move write_zeros_... call out of else.

Style only, no functional change. Requested by axeld.

src/system/kernel/cache/file_cache.cpp

@@ -1348,7 +1348,7 @@ file_cache_write(void* _cacheRef, void* cookie, off_t offset,
 				1, 0, &size);
 			*_size = size;
 			return error;
-		} else
+		}
 		return write_zeros_to_file(ref->vnode, cookie, offset, _size);
 	}