runtime(tiasm):  use correct syntax name tiasm in syntax script

closes: #16416

Signed-off-by: Wu, Zhenyu <wuzhenyu@ustc.edu>
Signed-off-by: Christian Brabandt <cb@256bit.org>
diff --git a/runtime/syntax/tiasm.vim b/runtime/syntax/tiasm.vim
index bdadc4a..c79596b 100644
--- a/runtime/syntax/tiasm.vim
+++ b/runtime/syntax/tiasm.vim
@@ -99,4 +99,4 @@
 hi def link tiasmType		Type
 hi def link tiasmFunction	Function
 
-let b:current_syntax = "lineartiasm"
+let b:current_syntax = "tiasm"