fix empty case in _count_svdvals

Author: stevengj

src/svd.jl

@@ -133,7 +133,8 @@ end
 
 # count positive singular values S ≥ given tolerances, S assumed sorted
 function _count_svdvals(S, atol::Real, rtol::Real)
-    tol = max(rtol * (isempty(S) ? zero(eltype(S)) : S[1]), atol)
+    isempty(S) && return 0
+    tol = max(rtol * S[1], atol)
     return iszero(S[1]) ? 0 : searchsortedlast(S, tol, rev=true)
 end