fix multiple solve handling

Author: ChrisRackauckas

ext/LinearSolveEnzymeExt.jl

@@ -83,12 +83,13 @@ function EnzymeCore.EnzymeRules.augmented_primal(config, func::Const{typeof(Line
         (dr.u for dr in dres)
     end
 
-    cache = (res, resvals, linsolve.val)
+    cache = (res, resvals)
     return EnzymeCore.EnzymeRules.AugmentedReturn(res, dres, cache)
 end
 
 function EnzymeCore.EnzymeRules.reverse(config, func::Const{typeof(LinearSolve.solve!)}, ::Type{RT}, cache, linsolve::EnzymeCore.Annotation{LP}; kwargs...) where {RT, LP <: LinearSolve.LinearCache}
-    y, dys, _linsolve = cache
+    y, dys = cache
+    _linsolve = linsolve.val
 
     @assert !(typeof(linsolve) <: Const)
     @assert !(typeof(linsolve) <: Active)
@@ -110,8 +111,8 @@ function EnzymeCore.EnzymeRules.reverse(config, func::Const{typeof(LinearSolve.s
     end
 
     for (dA, db, dy) in zip(dAs, dbs, dys)
-        z = if linsolve.cacheval isa Factorization
-            linsolve.cacheval' \ dy
+        z = if _linsolve.cacheval isa Factorization
+            _linsolve.cacheval' \ dy
         elseif linsolve.cacheval isa Tuple && linsolve.cacheval[1] isa Factorization
             linsolve.cacheval[1]' \ dy
         elseif linsolve.alg isa AbstractKrylovSubspaceMethod