kfdtest: update AtomicIncIsa for gfx12

"s_waitcnt 0" (deprecated in gfx12) is redundant here.

s_endpgm will wait for all outstanding instructions
to complete before executing.

Change-Id: Ia8b4dd0fd8dd713e7ba2cba9db85b7b12cee1dd4
Signed-off-by: Lang Yu <lang.yu@amd.com>

libhsakmt/tests/kfdtest/src/ShaderStore.cpp

@@ -183,7 +183,6 @@ const char *AtomicIncIsa =
             v_mov_b32 v2, -1
             flat_atomic_inc v3, v[0:1], v2 glc slc
         .endif
-        s_waitcnt 0
         s_endpgm
 )";