mumps: fixed compilation issues due to scotch not found at link time (#4567)

var/spack/repos/builtin/packages/mumps/package.py

@@ -92,14 +92,9 @@ def write_makefile_inc(self):
         orderings = ['-Dpord']
 
         if '+ptscotch' in self.spec or '+scotch' in self.spec:
-            join_lib = ' -l%s' % ('pt' if '+ptscotch' in self.spec else '')
             makefile_conf.extend([
                 "ISCOTCH = -I%s" % self.spec['scotch'].prefix.include,
-                "LSCOTCH = -L%s %s%s" % (self.spec['scotch'].prefix.lib,
-                                         join_lib,
-                                         join_lib.join(['esmumps',
-                                                        'scotch',
-                                                        'scotcherr']))
+                "LSCOTCH = {0}".format(self.spec['scotch'].libs.ld_flags)
             ])
 
             orderings.append('-Dscotch')