s/controla/controlla/g

Change-Id: I03c0f320181b969edb271cded8a80dcebd12334e
diff --git a/y2015/control_loops/python/arm.py b/y2015/control_loops/python/arm.py
index 52c1928..9fa270e 100755
--- a/y2015/control_loops/python/arm.py
+++ b/y2015/control_loops/python/arm.py
@@ -85,9 +85,9 @@
     self.A, self.B = self.ContinuousToDiscrete(
         self.A_continuous, self.B_continuous, self.dt)
 
-    controlability = controls.ctrb(self.A, self.B)
-    print 'Rank of augmented controlability matrix.', numpy.linalg.matrix_rank(
-        controlability)
+    controllability = controls.ctrb(self.A, self.B)
+    print 'Rank of augmented controllability matrix.', numpy.linalg.matrix_rank(
+        controllability)
 
     q_pos = 0.02
     q_vel = 0.300