[TF generation] Fix typo (#7582)

* Fixing top_k and min_length assertions, and a typo fix

* Apply suggestions from code review
Co-authored-by: Patrick von Platen <patrick.v.platen@gmail.com>

src/transformers/generation_tf_utils.py

@@ -225,7 +225,7 @@ class TFGenerationMixin:
         assert isinstance(do_sample, bool), "`do_sample` should be a boolean."
         assert isinstance(early_stopping, bool), "`early_stopping` should be a boolean."
         assert isinstance(use_cache, bool), "`use_cache` should be a boolean."
-        assert isinstance(num_beams, int) and num_beams > 0, "`num_beams` should be a strictely positive integer."
+        assert isinstance(num_beams, int) and num_beams > 0, "`num_beams` should be a strictly positive integer."
         assert temperature > 0, "`temperature` should be strictely positive."
         assert isinstance(top_k, int) and top_k >= 0, "`top_k` should be a positive integer."
         assert 0 <= top_p <= 1, "`top_p` should be between 0 and 1."