core: pvapi - set prev variable when dropping from cache

src/core/pvapi.c

@@ -289,6 +289,7 @@ int pv_cache_drop(void)
 				pkg_free(pvi);
 				return 1;
 			}
+			pvp = pvi;
 			pvi = pvi->next;
 		}
 	}
@@ -310,6 +311,7 @@ int pv_cache_drop(void)
 				pkg_free(pvi);
 				return 1;
 			}
+			pvp = pvi;
 			pvi = pvi->next;
 		}
 	}