rsa::KeyPair docs: Fix markdown formatting of nested bulleted list.

Address new complaints from Clippy.

src/rsa/keypair.rs

@@ -192,13 +192,13 @@ impl KeyPair {
  /// performance reasons and to avoid any side channels that such tests
  /// would provide.
  /// * Section 6.4.1.2.1, Step 6, and 6.4.1.4.3, Step 7:
- ///  * *ring* has a slightly looser lower bound for the values of `p`
+ /// * *ring* has a slightly looser lower bound for the values of `p`
  /// and `q` than what the NIST document specifies. This looser lower
  /// bound matches what most other crypto libraries do. The check might
  /// be tightened to meet NIST's requirements in the future. Similarly,
  /// the check that `p` and `q` are not too close together is skipped
  /// currently, but may be added in the future.
- ///  - The validity of the mathematical relationship of `dP`, `dQ`, `e`
+ /// * The validity of the mathematical relationship of `dP`, `dQ`, `e`
  /// and `n` is verified only during signing. Some size checks of `d`,
  /// `dP` and `dQ` are performed at construction, but some NIST checks
  /// are skipped because they would be expensive and/or they would leak
@@ -207,7 +207,7 @@ impl KeyPair {
  /// necessary, that can be done by signing any message with the key
  /// pair.
  ///
- ///  * `d` is not fully validated, neither at construction nor during
+ /// * `d` is not fully validated, neither at construction nor during
  /// signing. This is OK as far as *ring*'s usage of the key is
  /// concerned because *ring* never uses the value of `d` (*ring* always
  /// uses `p`, `q`, `dP` and `dQ` via the Chinese Remainder Theorem,