S5344: Fix 2**12 -> 2^12 (#3937)

rules/S5344/common/fix/bcrypt-parameters.adoc

@@ -6,7 +6,7 @@ More than 12 rounds.
 
 For bcrypt's key derivation function, the number of rounds should likewise be
 high enough to make the function slow enough to prevent brute force: More than
-4096 rounds `+(2**12)+`. +
+4096 rounds `+(2^12)+`. +
 This number is not the same coefficient as the first one because it uses
 a different algorithm.