Update FIPS hmac key documentation

The documentation is slightly incorrect about the FIPS hmac key.

CLA: trivial

Reviewed-by: Shane Lontis <[email protected]>
Reviewed-by: Tim Hudson <[email protected]>
Reviewed-by: Matt Caswell <[email protected]>
(Merged from openssl#23846)

INSTALL.md

@@ -530,7 +530,7 @@ Setting the FIPS HMAC key
 
 As part of its self-test validation, the FIPS module must verify itself
 by performing a SHA-256 HMAC computation on itself. The default key is
-the SHA256 value of "the holy handgrenade of antioch" and is sufficient
+the SHA256 value of "holy hand grenade of antioch" and is sufficient
 for meeting the FIPS requirements.
 
 To change the key to a different value, use this flag. The value should