Corrected spelling mistake

Author: Yashas17

maintainer/walberla_kernels/lees_edwards.py

@@ -40,7 +40,7 @@ def type_all_numbers(expr, dtype):
 
 def velocity_offset_eqs(config, method, pdfs,
                         shear_dir_normal, stencil, combined_kernel=True):
-    """Calculates the difference between quilibrium pdf distributions
+    """Calculates the difference between equilibrium pdf distributions
     with (rho, u) and (rho, u+v) and applies them to out-flowing
     populations in the boundary layer. Returns an AssignmentCollection
     with one Assignment per stencil direction.