dbghelp: Check file handles against INVALID_HANDLE_VALUE, not NULL.

dlls/dbghelp/msc.c

@@ -2308,7 +2308,7 @@ BOOL pdb_fetch_file_info(struct pdb_lookup* pdb_lookup)
 
     if (image) UnmapViewOfFile(image);
     if (hMap) CloseHandle(hMap);
-    if (hFile) CloseHandle(hFile);
+    if (hFile != INVALID_HANDLE_VALUE) CloseHandle(hFile);
 
     return ret;
 }

dlls/dbghelp/pe_module.c

@@ -142,7 +142,7 @@ static BOOL pe_load_dbg_file(const struct process* pcs, struct module* module,
 
     if (dbg_mapping) UnmapViewOfFile(dbg_mapping);
     if (hMap) CloseHandle(hMap);
-    if (hFile != NULL) CloseHandle(hFile);
+    if (hFile != INVALID_HANDLE_VALUE) CloseHandle(hFile);
     return ret;
 }