Merge pull request #1054 from InfiniTensor/issue/1033c

issue/1033 - fix xmake.lua for fa target

Author: wooway777

xmake.lua

@@ -462,7 +462,7 @@ target("infinicore_cpp_api")
     add_linkdirs(INFINI_ROOT.."/lib")
     add_links("infiniop", "infinirt", "infiniccl")
 
-    if get_config("flash-attn") ~= nil then
+    if get_config("flash-attn") == true then
         add_installfiles("(builddir)/$(plat)/$(arch)/$(mode)/flash-attn*.so", {prefixdir = "lib"})
         if has_config("nv-gpu") then
             add_deps("flash-attn-nvidia")