Simplify fast_dot.

Author: mblondel

sklearn/utils/extmath.py

@@ -155,13 +155,15 @@ def fast_dot(A, B):
     if LooseVersion(np.__version__) < '1.7.2':  # backported
         try:
             linalg.get_blas_funcs(['gemm'])
-            try:
-                return _fast_dot(A, B)
-            except ValueError:
-                return np.dot(A, B)
         except (AttributeError, ValueError):
             warnings.warn('Could not import BLAS, falling back to np.dot')
             return np.dot(A, B)
+
+        try:
+            return _fast_dot(A, B)
+        except ValueError:
+            # Maltyped or malformed data.
+            return np.dot(A, B)
     else:
         return np.dot(A, B)