Replace CHECK_ERROR macros with a check() helper using std::source_location

Add la::petsc::check(ierr, petsc_function), a thin wrapper around
error() that throws on a non-zero PETSc error code. Both take a
std::source_location defaulted to the call site, so error() no longer
needs a caller-supplied __FILE__ and reports the exact line, not just
the file.

Being a plain namespaced function rather than a macro, check() is
usable from header-inline code, so it also replaces the private
CHECK_ERROR macros duplicated across la/petsc.cpp, la/slepc.cpp,
fem/petsc.h, and nls/SNESSolver.cpp, and the leftover explicit
if (ierr != 0) sites in la/petsc.h and fem/petsc.cpp that those macros
couldn't reach.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

Author: jhale

cpp/dolfinx/fem/petsc.cpp

@@ -57,8 +57,7 @@ Vec fem::petsc::create_vector_block(
   PetscErrorCode ierr
       = VecCreateGhost(maps[0].first.get().comm(), local_size, PETSC_DETERMINE,
                        _ghosts.size(), _ghosts.data(), &x);
-  if (ierr != 0)
-    la::petsc::error(ierr, __FILE__, "VecCreateGhost");
+  la::petsc::check(ierr, "VecCreateGhost");
 
   return x;
 }
@@ -85,8 +84,7 @@ Vec fem::petsc::create_vector_nest(
   Vec y;
   PetscErrorCode ierr = VecCreateNest(vecs.front()->comm(), petsc_vecs.size(),
                                       nullptr, petsc_vecs.data(), &y);
-  if (ierr != 0)
-    la::petsc::error(ierr, __FILE__, "VecCreateNest");
+  la::petsc::check(ierr, "VecCreateNest");
 
   return y;
 }