wasm: fix arch detect on windows with WASM_OBJECT_FILES

Fixes: QTBUG-79146
Change-Id: I00188013b98687f34582aeb7b29b6d7439334536
Reviewed-by: Morten Johan Sørvig <morten.sorvig@qt.io>
Reviewed-by: Edward Welbourne <edward.welbourne@qt.io>

config.tests/arch/write_info.pri

@@ -4,10 +4,7 @@ targetinfofile ~= s/pro$/target.txt/
 win32 {
     ext = .exe
 } else:wasm {
-    equals(WASM_OBJECT_FILES, 1): \
-        ext = .o
-    else: \
-        ext = .wasm
+    ext = .wasm
 }
 
 content = $${file_prefix}$${TARGET}$${ext}