Update src/tangent_types/tangent.jl

Co-authored-by: github-actions[bot] <41898282+github-actions[bot]@users.noreply.github.com>

Author: mzgubic

src/tangent_types/tangent.jl

@@ -58,7 +58,7 @@ end
 
 function _backing_error(P, G, E)
     msg = "Tangent for the primal $P should be backed by a $E type, not by $G."
-    throw(ArgumentError(msg))
+    return throw(ArgumentError(msg))
 end
 
 function Base.:(==)(a::Tangent{P,T}, b::Tangent{P,T}) where {P,T}