doc: fix return type of `crypto.getFips()`

`crypto.getFips()` returns a number, not a boolean.

PR-URL: https://github.com/nodejs/node/pull/32580
Reviewed-By: Colin Ihrig <cjihrig@gmail.com>
Reviewed-By: James M Snell <jasnell@gmail.com>
Reviewed-By: Luigi Pinca <luigipinca@gmail.com>
Reviewed-By: Anna Henningsen <anna@addaleax.net>
Reviewed-By: Tobias Nießen <tniessen@tnie.de>
Signed-off-by: Richard Lau <riclau@uk.ibm.com>

doc/api/crypto.md

@@ -2308,8 +2308,8 @@ console.log(aliceSecret === bobSecret);
 added: v10.0.0
 -->
 
-* Returns: {boolean} `true` if and only if a FIPS compliant crypto provider is
-  currently in use.
+* Returns: {number} `1` if and only if a FIPS compliant crypto provider is
+  currently in use, `0` otherwise.
 
 ### `crypto.getHashes()`
 <!-- YAML