fix mul!() return type

Author: alyst

src/dual.jl

@@ -856,12 +856,12 @@ for MT in (StridedMatrix{<:LinearAlgebra.BlasFloat},
         _map_dual_components!((y, x) -> ldiv!(y, m, x), (y, x, _) -> ldiv!(y, m, x), similar(x), x)
 
     @eval LinearAlgebra.mul!(C::StridedVector{T}, A::$MT, B::StridedVector{T}) where T <: Dual =
-        mul!(reinterpret(reshape, valtype(T), C), reinterpret(reshape, valtype(T), B), A')
+        (mul!(reinterpret(reshape, valtype(T), C), reinterpret(reshape, valtype(T), B), A'); C)
 
     @eval LinearAlgebra.mul!(C::StridedVector{T}, A::$MT, B::StridedVector{T},
                              α::Union{LinearAlgebra.BlasFloat, Integer},
                              β::Union{LinearAlgebra.BlasFloat, Integer}) where T <: Dual =
-        mul!(reinterpret(reshape, valtype(T), C), reinterpret(reshape, valtype(T), B), A', α, β)
+        (mul!(reinterpret(reshape, valtype(T), C), reinterpret(reshape, valtype(T), B), A', α, β); C)
 
     @eval Base.:*(m::$MT, x::StridedVector{<:Dual}) = mul!(similar(x, (size(m, 1),)), m, x)