Fix compiler warnings

-Wdeprecated-declarations:
  Replace deprecated xmlXPathInit() with xmlInitParser()[1]

-Wmaybe-uninitialized:
  `fil1` was initialized to 0 in commit 0138220f to fix compiler
  warnings, but `fil2` was missed.

ref:
[1]: https://gnome.pages.gitlab.gnome.org/libxml2/devhelp/libxml2-xpath.html#xmlXPathInit

storage/connect/libdoc.cpp

@@ -600,7 +600,7 @@ xmlNodeSetPtr LIBXMLDOC::GetNodeList(PGLOBAL g, xmlNodePtr np, char *xp)
     if (trace(1))
       htrc("Calling xmlPathInit\n");
 
-    xmlXPathInit();
+    xmlInitParser();
 
     if (trace(1))
       htrc("Calling xmlXPathNewContext Docp=%p\n", Docp);

storage/connect/tabext.cpp

@@ -330,7 +330,7 @@ bool TDBEXT::MakeSrcdef(PGLOBAL g)
 	char *catp = strstr(Srcdef, "%s");
 
 	if (catp) {
-		char *fil1 = 0, *fil2;
+		char *fil1 = 0, *fil2 = 0;
 		PCSZ  ph = ((EXTDEF*)To_Def)->Phpos;
 
 		if (!ph)