fix the linter

Author: fchapoton

src/sage/rings/polynomial/multi_polynomial_ring_base.pyx

@@ -623,8 +623,8 @@ cdef class MPolynomialRing_base(CommutativeRing):
             if self is other:
                 return True
             n = other.ngens()
-            check =  (self.ngens() >= n and
-                      self.variable_names()[:n] == other.variable_names())
+            check = (self.ngens() >= n and
+                     self.variable_names()[:n] == other.variable_names())
             if other.base_ring is base_ring and check:
                 return True
             elif base_ring.has_coerce_map_from(other._mpoly_base_ring(self.variable_names())):