gen_valid doc formatting fix

Change-Id: Ib34b51835b2b26b6475b3feb288dd1bbee6f0705
Signed-off-by: Michael Walsh <micwalsh@us.ibm.com>
diff --git a/lib/gen_valid.py b/lib/gen_valid.py
index aaf5213..02ba515 100755
--- a/lib/gen_valid.py
+++ b/lib/gen_valid.py
@@ -591,8 +591,8 @@
 
     invalid_values                  A dictionary whose entries correspond to the entries in var_value.  Each
                                     value in invalid_values is itself an invalid_values list for the
-                                    corresponding value in var_value.  For any var_value[key] to be considered
-                                    valid, its value must NOT be found in invalid_values[key].
+                                    corresponding value in var_value.  For any var_value[key] to be
+                                    considered valid, its value must NOT be found in invalid_values[key].
     """
 
     error_message = ""