restore pure attribute

Author: perazz

src/stdlib_linalg.fypp

@@ -304,7 +304,7 @@ module stdlib_linalg
         !> Matrix determinant
         ${rt}$ :: det
     end function stdlib_linalg_${rt[0]}$${rk}$determinant
-    module function stdlib_linalg_pure_${rt[0]}$${rk}$determinant(a) result(det)
+    pure module function stdlib_linalg_pure_${rt[0]}$${rk}$determinant(a) result(det)
         !> Input matrix a[m,n]
         ${rt}$, intent(in) :: a(:,:)
         !> Matrix determinant

src/stdlib_linalg_determinant.fypp

@@ -16,7 +16,7 @@ submodule (stdlib_linalg) stdlib_linalg_determinant
      ! BLAS/LAPACK backends do not currently support xdp
      #:for rk,rt in RC_KINDS_TYPES
      #:if rk!="xdp" 
-     module function stdlib_linalg_pure_${rt[0]}$${rk}$determinant(a) result(det)     
+     pure module function stdlib_linalg_pure_${rt[0]}$${rk}$determinant(a) result(det)     
      !!### Summary
      !! Compute determinant of a real square matrix (pure interface).
      !!