Should return nothing

Author: ErikQQY

src/FastAlmostBandedMatrices.jl

@@ -137,7 +137,7 @@ end
 function Base.fill!(A::AlmostBandedMatrix, v)
     fill!(bandpart(A), v)
     fill!(fillpart(A), v)
-    return A
+    return nothing
 end
 
 @inline function colsupport(::AbstractAlmostBandedLayout, A, j)