[Bug translation/90160] missing quote in diagnostic

[roland.illig at gmx dot de]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=90160

--- Comment #2 from Roland Illig <roland.illig at gmx dot de> ---
From gcn.c:

  error ("unknown specifier %s in amdgpu_hsa_kernel attribute", str);